Poster Session

Lorena Sánchez Moreno (Ph.D. student)
Northvolt AB & Uppsala University, Sweden

Ni-rich NMC (LiNi0_.92Co_0.04Mn_0.04O₂) cathode materials in Li-ion batteries (LIBs) offer high capacity, enhancing cell energy density. However, they face challenges like rapid capacity degradation and poor structural stability. Effective stabilization methods include surface (coating) modifications. Boron (B) has emerged as a widely adopted element in surface coatings to improve Ni-rich NMCs’ performance. Yet, the exact mechanisms of B’s positive impact remain unclear due to its complex interactions with NMC. Our study investigates Ni-rich NMC degradation and B’s influence through comprehensive characterization methods before, during, and after cycling. Analytical tools like XRD, XPS, SEM, and electrochemical techniques help examine surface properties. We correlate NMC failure modes with B’s effects, aided by collaborations between Northvolt and Uppsala University, promising advancements in battery research and industry.

David Wragg (Researcher)
Institute for Energy Technology, Norway

Degradation mechanisms in commercial pouch cells (LG JP3) have been studied extensively with electrochemical methods, characterizing state of health and response to various cycling regimes and conditions. To date few links have been made between cycling data for these large cells and the chemical reactions that lead to degradation. Disassembly of JP3 cells cycled under a range of conditions has provided us with many electrode sheets that show visible signs of damage. We have used synchrotron XRD and XRF to map the elemental and crystal structure composition of the electrodes with a spatial resolution of less than 50 microns. Analysis of the XRD data with surface Rietveld methods allows us to extract crystal structure and microstructure parameters for any point in the datasets.

Arjun Muralidharan (Ph.D. student)
Aalto University, Finland

Emerging battery technologies boost energy density, lifespan, and safety. However, the increasing use of lithium-ion batteries (LIBs), coupled with material scarcity and recycling challenges like inefficient processes, and batteries containing various elements, results in low-quality recovered materials. Discharged voltage below 0% state of charge (SOC) is proposed to enable more efficient recycling methods. While aqueous NaCl was suggested, experiments revealed its high corrosiveness during discharge. Experimentation with various inorganic salts in aqueous solutions aimed to achieve low discharge voltage, but water-splitting reactions persisted due to the high voltage of LIBs. Therefore, the organic solvents and ionic liquids in non-aqueous media offer the electrochemical window to maintain stable electrolytes and help mitigate casing corrosion.

Ola Willstrand (Ph.D. student)
RISE Research Institutes of Sweden & Uppsala University, Sweden

Thermal runaway in Li-ion batteries is associated with rapid heat release rate, large volume of gas production, and violent burning behavior. The focus of battery safety standards is usually to prevent thermal runaway from happening, but that does not eliminate the need for characterization of thermal runaway events. This is an area not well standardized, leading to employment of various test setups, test scenarios, analysis techniques, and interpretation of results.
The main objectives of this work are to investigate the impact of different factors, such as state of charge, thermal runaway triggering methods, ambient atmosphere, and cell size, on the gas generation, gas composition, temperature development, heat generation and mass loss. An important finding is the significant effect from the thermal runaway triggering method, which potentially affects thermal propagation characteristics in battery systems.

Marie Uth (Ph.D. student)
Danish Graphene, Denmark

When adding graphene to spinel LNMO electrodes an increased cycling stability is observed. The lateral size of the graphene sheets and the degree of oxidation affect the performance of the electrode. The presented work shows the optimal graphene concentration for a small flake additive with medium oxidation. The graphene additive can be added as a paste in the slurry mixing step for easy implementation in established electrode preparation procedures. The graphene additive stabilizes the electrochemical transitions under long-term cycling, which results in higher capacity retention.

Yaprak Subasi (Ph.D. or Postdoc)
Uppsala University, Sweden

Many efforts have been devoted to the development of high-performance cathode materials for sodium-ion batteries to make them fully competitive to lithium-ion batteries. Na₄Fe₃(PO₄)₂(P₂O₇) (NFPP) is regarded as a promising cathode material due to its non-toxicity, high average working voltage, favorable theoretical capacity, low volume changes as well as structural and thermal stability. However, its practical use is limited because of the formation of impurity phases and low intrinsic electronic conductivity. Various strategies have been developed to enhance conductivity such as nanosizing, carbon coating, metal ion doping. In this study, Na₄Fe_3-xM_x(PO₄)₂(P₂O₇) (M: Mn, Ni, or Zn) composites are synthesized to improve capacity and energy density. The structure and morphology of doped NFPP are characterized by X-ray diffraction and scanning electron microscopy techniques. The electrochemical performance is investigated in half-cells via galvanostatic charge-discharge cycling tests.

Alisa R. Bogdanova (Ph.D. student)
Aalto University, Finland

Lithium-ion batteries are a promising type of energy storage devices owing to their optimal combination of performance metrics. However, further advancements require improved battery performance and more efficient manufacturing technologies to address environmental issues. The conventional manufacturing process is energy and resource intensive, involving the dissolution of electrochemically inactive polyvinylidene fluoride binder in the hazardous solvent N-methyl-2-pyrrolidone. Recently, carbon nanotubes have gained interest for dry electrode manufacturing due to their high conductivity and mechanical properties, replacing inactive components. In this work, we employed the concept of in situ gas-phase mixing of single-walled carbon nanotubes (SWCNTs) with aerosolized LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) to obtain binder- and solvent-free electrodes with 99.8 wt% of NMC811. The NMC-SWCNT composite electrodes show high conductivity, rate capability, and enhanced cycling performance.

Varsha Joseph Ariyamparambil (Ph.D. student)
Linköping University, Sweden

Zinc-ion batteries have a huge potential to replace lithium-ion batteries due to their abundant resources and high safety. However, their cyclic stability and energy density need to be improved to compete with lithium-ion batteries. To bridge this gap, research is being done on electrode material, electrolyte, and cell design. Herein, we designed a highly ionic conductive and stable electrolyte, which we accomplished by creating a hydrogel carefully engineered using the water-in-salt electrolyte concept. This eventually led to achieve long-life cycle platting/stripping of Zn. Later, we demonstrated a zinc-Lignin battery having good capacity and cyclic stability.

Sherif Hegazy (Ph.D student)
University of Oulu, Finland

Catalytic graphitization of biomass-derived carbon materials presents a promising approach for energy-efficient carbon synthesis. In this study, we investigate the effect of metallic catalysts on the degree of graphitization and electrochemical performance of carbon precursors obtained from hydrothermal carbonization (HTC) of sawdust. We employed Fe, B, and Mo as catalysts at 800°C and 1000°C. The ID/IG ratios obtained from Raman spectroscopy indicated significant graphitization: at 800°C, the ID/IG values were 1.97 for HTC alone, and 0.71, 1.05, and 1.42 for Fe, B, and Mo, respectively. At 1000°C, these values shifted to 1.3 for HTC alone, and 0.69, 0.86, and 0.69 for Fe, B, and Mo, respectively, indicating higher graphitization at the higher temperature. Comprehensive characterization included BET analysis, (SEM), (XRD), This research contributes the understanding of biomass-derived carbon materials’ catalytic graphitization to replace current synthetic and natural graphite in bat

Meghdad Hosseinzadegan (Ph.D. student)
Uppsala University, Sweden

Sodium-ion batteries (SIBs) are the prime alternative to reduce the over-reliance on lithium-ion batteries (LIBs) due to Na and Li similarities, as well as abundancy of Na resources. Finding a high energy density negative electrode is one of the main challenges for SIBs. Although sodium metal has the highest energy density, nonuniform sodium metal growth (e.g., dendrites) can cause short-circuits.
Since the current densities applied during conventional cycling are insufficient to induce a densely populated nucleation event, high overpotential pulses were applied to generate numerous nuclei simultaneously.
Chronopotentiometry, scanning electron microscopy (SEM) as well as operando optical microscopy were performed on symmetrical Na-cells. Results show that a combination of +4 V, and -6 V (both vs. Na+/Na) are most effective to decrease the overpotential during following galvanostatic stripping/ plating. SEM analysis is in agreement showing stabilised and planar Na-metal growth.

Anna Kobets (Ph.D. student)
Aalto University, Finland

Ni-rich layered oxides like NMC811 are promising positive electrode materials with high specific capacity (200 mAh/g) and energy density, but suffer from rapid capacity decline, structural disorder, and side reactions. Incorporating electrochemically inactive elements like Mg stabilises the layered structure and suppresses Ni ion migration. Calcination conditions during lithiation are crucial for controlling morphology, doping effectiveness, and crystal structure, determining electrochemical behaviour. This work uses three NMC811 precursors with 0, 0.25, and 0.50 at.% Mg content, adding 0.75 at.% Mg during lithiation. The research investigates phase changes via in-situ high-temperature XRD and primary particle growth via SEM at various calcination temperatures to understand the relationship between structural features and electrochemical performance. Combining two types of doping increases specific capacity and stability after 100 cycles at the 3.0-4.6 V vs. Li potential range.

Johan Jean-Claude Maurice Hamonnet
Norges teknisk-naturvitenskapelige universitet (NTNU), Norway

LiNi_0.5Mn_1.5O₄ (LNMO) is a promising high voltage and co-free cathode material for lithium-ion batteries (LiBs) applications. In this work, ionic liquids are being used to develop alternative electrolytes for batteries with enhanced cycling stability and performance.
The electrochemical properties of LNMO/Li half cells with an ionic liquid electrolyte (ILE) composed of 0.79 molal LiFSI in P111i4FSI (figure 1a) are reported. These results are compared to those of the same half-cell with a more conventional 1M LiPF₆ in 1:1 ethyl carbonate (EC): diethyl carbonate (DEC) electrolyte (LP40) and at different temperatures. The cells using the P_111i4FSI-based electrolytes were more stable, with a discharge capacity still >115 mAh/g at the end of the cycle (figure 1b).
Postmortem analysis showed that the structural integrity of the LNMO particles was significantly damaged after cycling with the LP40 electrolyte and mostly intact with the ILE.

Agnes-Matilda Mattson (Ph.D. student)
Uppsala University, Sweden

Most batteries today consist of expensive and scarce metals such as lithium and cobalt. In order to meet the increased demands, other chemistries need to be investigated, for example Sodium-ion batteries (NIBs). An interesting cathode material for NIBs is Prussian White (PW), that is both environmentally friendly and cheap. During use in a battery PW undergoes a phase transition that induces a large volume change. It has been proposed that small ions or neutral guest molecules could mitigate this volume change. In this work the use of lithium to stabilise the framework of PW was investigated using galvanostatic cycling to synthesise the material and Operando XRD to study the phase transition occurring during cycling. The results show that lithium can stabilise the framework by shifting the detrimental phase transition to a higher SOC. As a result, a larger potential window can be utilised without detrimental structural degradation occurring during cycling of the battery.

Artem Faustov (Ph.D. student)
Aalto University, Finland

LFP batteries are finding a number of roles in EV and ESS. The drawback of LFP is in moderate specific/volumetric energy densities compared to Co-based cells.
An increase of active material is one of the way to improve these characteristics. SWCNT is bundles of long and flexible nanotubes with high electronic conductivity, can be used in lower amount than carbon black, current conductive additive industrial standard. The author conducted experiments which demonstrate that an usage of SWCNT as conductive additive allows to increase LFP content up to 98% and lead to rate performance and significant cycle life improvement.
Differential capacity done for rate tests shows peak’s shifting. At the same time, no signs of LFP degradation or morphology change is observed for cycled cathodes.
It seems that a mechanical cathode degradation leads to worsening of electrochemical performance. An usage of CNT leads to electrode structure hardening decreasing mechanical degradation during the cycling

Chanez Maouche (Ph.D. / Postdoc)
University of Turku, Finland

The development of high-density, high-safety, and cost-effective energy storage devices is critical for efficiently utilizing intermittent renewable energy resources. Flow batteries (FBs) are highly promising due to their ability to store large amounts of energy, modularity, and superior safety. FBs consist of two circulating redox couples stored in external electrolyte tanks, storing energy via redox reactions of reduced (negolyte) and oxidized (posolyte) electrolytes. However, the wide-scale use of FBs is limited by cost of redox-active metals. Quinones a promising class of energy storage materials are ongoing research focusing on improving their stability, solubility and performance with a particular emphasis on the creation of stable negolytes. Here, we introduced aza-quinone (AZ) compounds as novel negolytes in FB systems. The electrochemical performance of AZ was evaluated by cyclic voltammetry under various conditions and in FBs at high concentrations to assess their stability.

Marte Skare (Ph.D. student)
Institute of Energy Technology (IFE), Norway

Binary Si-based compounds like SiC_x have demonstrated potential to reduce the capacity fade normally experienced by Si anodes during cycling in Li-ion batteries, but the mechanisms are still unclear. By depositing amorphous SiC_x thin films using PECVD, the films stoichiometry and thickness can be readily modified to facilitate a controlled analysis of the materials inherent properties as well as their dependence on the materials composition.
A set of four 70nm thick films has been studied, with four compositions ranging from pure Si to SiC₃₉. XPS confirms formation of SiCx with increasing CH₄ to SiH₄ ratio during deposition resulting in an increase in Si-C bonds. Grazing-Incidence Pair Distribution Function (GI-PDF) reveal that more carbon also results in reduced long-range order. In electrochemical experiments, increasing carbon content results in lower reversible capacity and initial coulombic efficiency but show signs of differing lithiation mechanisms in dQ/dV analysis.

Jinsong Hua (Researcher)
(Institute for Energy Technology (IFE), Norway)

Lithium-ion batteries suffer from degradation caused by their operational conditions and consequently have a limited lifetime within their first application. These batteries might be available for re-use in a different application, commonly under more moderate usage conditions. The influence of such a change in operating conditions on battery degradation within a second life application is not very well understood.
Here we present the parameterization and subsequent extension of an empirical degradation model that formulates the degradation process as a function of battery operations for both, first- and second life applications. We focus on a commercial 64 Ah NMC-graphite pouch cell. The model parametrization is based on a large dataset containing both calendar and cycle life data of more than 100 cells, covering a large window of temperatures (5-45 °C), C-rates (0.2-1.5 C), SoC windows, and average SoC.

Carl Erik Lie Foss (Researcher)
(Institute for Energy Technology (IFE), Norway)

Slot-die coating is a leading method for industrial-scale anode production due to its high throughput and low operating cost. Transitioning from small lab-scale slurry coating to large-scale production requires optimal slurry composition. Key factors include a low capillary number, achieved through low viscosity, slow foil speed, and high surface tension. However, low viscosity can cause the slurry to run and slow foil speed can reduce production volumes and lead to clogging. The combination of conductive additives, graphite, binder, and solvent content (type and pH) significantly impacts slurry properties. Investigating all possible compositions to optimize these properties is time-consuming. This study aims to minimize the required slurry compositions while obtaining valuable data by using design of experiments (DOE), which is a systematic, efficient method for studying the relationship between multiple input variables and key output variables.

Tove Ericson (Ph.D. / Postdoc)
Uppsala University, Sweden

Silicon and SiO₂ shows high theoretical storage capacities as anode materials for Li-ion batteries but are challenging to use due to massive volume expansion at Li insertion. One way to counteract this is to use nanostructures. However, the production of such structures often requires complicated methods and hazardous chemicals. A more sustainable approach is to use biosilica produced by organisms, for example diatoms, a unicellular photosynthetic microalgae. The capacity of the naturally produced nano-SiO₂ can then be further improved by reducing the material to SiO_x. To develop functional batteries based on these species, it is essential to understand the composition, depth profile and stability of the surface layer created when cycling (SEI). Here we use synchrotron radiation with different energies to investigate the SEI layer for this new battery material, cycled with various electrolytes, to enable integration of this sustainably sourced feedstock into battery technology.

Sofia Reiner (Ph.D. student)
Chalmers University of Technology, Sweden

In previous studies on lithium-ion batteries, an extended voltage hold during discharge has been shown to improve capacity retention of the cell. In NMC/graphite cells, similar trends have been observed but the mechanisms behind the capacity recovery after voltage holds are not fully understood, and mechanisms connected to the evolution of the solid electrolyte interphase (SEI) cannot be excluded. At the same time, voltage holds are often used in sample preparation for X-ray photoelectron spectroscopy (XPS) studies on electrodes to ensure stable electrode potentials. But what if these voltage holds change the SEI or the general surface composition? Therefore, we study the effect of extended voltage holds on the SEI layer in graphite electrodes with XPS. Furthermore, we present a study into important factors when measuring battery interphases, such as the SEI and areas of plated lithium on graphite. These include the impact of chosen measuring spots, cell type and sample homogeneity.

Paula Keski-Korsu-Piekkari (Ph.D. student)
University of Oulu, Finland

In recent studies for safer and efficient batteries, solid state polymer electrolytes (SSPE) have received increasing interest. PVDF is a widely studied binder for SSPE, but it usually needs (inorganic) fillers or ionic liquid (IL) for better ionic conductivity [1, 2]. In this study, we compare PVDF-HFP and commercial Daikin VT475 polymers with MPPyrTDI as IL and two different Li-salts. The ionic conductivity (IC) achieved with PVDF-HFP was 1.11∙10-3 S/cm, whereas with VT475 IC was 1.47∙10-3 S/cm. Various solvents were tested to better understand the membrane formation and its mechanical properties. All membranes were made inside Ar glove box and dried under low vacuum with 300 Torr and 60°C overnight. Membranes of both polymers were colourless, soft, and flexible films. Importantly, higher IL content resulted in poor membrane formation due to difficulties in evaporation. NMP as a solvent provided the best IC with VT475 and LiFTSI salt.

Gian Marco Trippetta (Ph.D. student)
KTH Royal Institute of Technology, Sweden

Recent teardown analyses of high-energy Li-ion batteries have revealed a considerable heterogeneity in their degradation, with Li plating as a dominant factor. This presentation will describe a method for rapid estimation of the extent of lithium plating in a high-energy Li-ion battery. Material characterization was performed, using 7Li NMR to quantify Li-plating in different locations. The experimental results were then correlated with a high-definition image analysis, performed by a colour detection algorithm on the scanned electrodes sheets. To produce more accurate results, this protocol was also carried out on the separator, as a significant amount of lithium plating was found adhered to it after tear-down. Finally, results were compared with an electrochemistry-based method called OLSA (OCP-based Local SOH Assessment) to experimentally evaluate how the SOH heterogeneous pattern correlates with lithium plating.

Yan Lin (Ph.D. student)
University of Oulu, Finland

Spinel LiNi_0.5Mn_1.5O₄ (LNMO) is a top candidate for the next generation high-energy and high-power lithium-ion battery cathodes due to its high operating voltage (4.7 V vs. Li+/Li), exceptional specific energy density, impressive rate performance, and cost-effectiveness. The electrochemical properties of LNMO vary significantly between its Ni/Mn ordered P₄332 phase and the disordered Fd3m phase, underscoring the importance of achieving specific Ni/Mn arrangements for optimal performance.
In this study, LNMO with varying particle sizes was controllably synthesized using a facile scalable co-precipitation method. The impact of oxygen vacancies on the Ni/Mn arrangement within the LNMO crystal structure was meticulously analyzed using Synchrotron XRD with Rietveld analysis, HRTEM, and XPS. Additionally, in-situ XRD measurement was conducted to delve into the mechanisms of lithium storage within the material, providing deeper insights into its functional dynamics during battery operation.

Carlos Antonio Rupisan (Ph.D. student)
Aalto University, Finland

Open Circuit Voltage (OCV) behavior of lithium-ion batteries is an important component for modelling applications such as parameter estimation, degradation modelling and state-of-charge estimation, as it represents the static behavior of the battery. One method to obtain this behavior is the Galvanic Intermittent Titration Test (GITT). However, GITT does not have a standard for the relaxation time test parameter, and the amount of time needed to get to open circuit state can be long. This study investigates the effect of shortening the relaxation time for high capacity bare and coated LiNi0.8Mn0.1Co0.1O2 (NMC811) batteries tested at high cutoff potential (4.5 V vs graphite) on battery modelling such as parameter fitting using an equivalent circuit and degradation modelling. Initial results show feasibility to shorten total GITT time by 66% by shortening the relaxation time parameter from a base assumption of 2h to 30min with 2% difference in modelling error for parameter estimation.

Princess Stephanie Llanos (Ph.D. student)
Aalto University, Finland

Employing high capacity LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) as a cathode material can help deliver high-energy-density lithium-ion batteries. However, a high voltage operation can lead to irreversible side reactions at the electrode-electrolyte interface which result in drastic capacity fade. In this work, a stable nanoscale lithium fluoride (LiF) coating is deposited on the NMC811 electrode via atomic layer deposition to address the interfacial instability issues. The LiF coating serves as an artificial cathode electrolyte interface (CEI) and prevents the direct contact between NMC811 and electrolyte to suppress harmful parasitic reactions during cycling. LiF-NMC811 delivers higher capacity retention than uncoated NMC811 after 100 cycles at a high cutoff potential for half-cell (3.0-4.6 V vs Li/Li+) and full-cell (2.8-4.5 V vs graphite) configurations. As LiF is a main component in the CEI, the study highlights the impact of CEI in NMC-based cathodes.

Rafal Sliz (Prof.)
University of Oulu, Finland

As the use of NMP as a solvent becomes increasingly restricted, significant efforts are being directed towards identifying sustainable, non-toxic alternatives that provide comparable dissolving properties. While Cyrene, KJCMPA, PolarClean, etc., show promising outcomes, they present challenges in processing, and the resulting battery components often do not match the performance of those produced with NMP. Additionally, when creating multilayer battery architectures through additive manufacturing, the interfacial interactions are crucial.
This work introduces an innovative multisolvent approach that utilizes a minimal amount of NMP in a pre-dissolving stage, followed by the use of a sustainable solvent as the primary medium for slurry creation and further processing. This solvent engineering strategy enables the formulation of slurries with tailored properties, facilitating the controlled deposition of battery multilayer structures with highly adhesive interfaces.

Esther Poncy Mathew (Ph.D. student)
SINTEF, Norway

LNMO (Lithium Nickel Manganese Oxide), a high-voltage spinel compound, is a promising cathode material to power future electric vehicles when coupled with silicon-based anodes. Pre-lithiation strategies using sacrificial salts are studied to improve its cycling performance. Lithium oxalate, a well-studied pre-lithiation salt which is cheap and compatible with the standard cathode processing protocol is investigated. Different methods to overcome the kinetic hurdles of salt decomposition is studied to enable the full utilization of the pre-lithiation salt. The salt incorporation into the cathode material is optimised and the cycling behaviour of lithium oxalate enriched LNMO is analysed.

August Johansson (Researcher)
SINTEF, Norway

BattMo [1] is an open-source framework for simulating electrochemical-thermal devices jointly developed by electrochemists, physicists, and applied mathematicians. It is primarily developed for Li-ion batteries described by PXD (X=2,3,4) Doyle-Fuller-Newman models, and has been tested and verified on various electrode materials, including SiGr, NMC, LFP, and LNMO, as well as standard formats such as coin, pouch, and cylindrical cells. Its modular design allows for application to other systems such as magnesium batteries and electrolysers. BattMo is developed in MATLAB and also has a fast Julia version called BattMo.jl [2] in development. This contribution presents the key features of the software, especially its parameterization capabilities, how simulations can be fully described in JSON format, and its GUI [3]. Documentation is available at [4].

1. www.github.com/BattMoTeam/BattMo
2. www.github.com/BattMoTeam/BattMo.jl
3. app.batterymodel.com
4. www.battmoteam.github.io/BattMo-doc

Guiomar Hernández
Uppsala University, Sweden

With the increasing battery production and demand, not only the choice of materials should be considered for sustainability purposes but also the processes involved. These should be more environmentally friendly, energy efficient and avoid the use of toxic components. The Horizon Europe project NoVOC “Eliminating VOC from battery manufacturing through dry or wet processing” aims to develop more sustainable electrode manufacturing processes for NMC811 and silicon-graphite composites including both aqueous-based and dry formulations. In addition, the project aims to reduce or omit PFAS-based compounds with fluorine-free alternatives. Herein, the most recent results of the project will be presented.

Glaydson Simoes dos Reis (Researcher)
Swedish University of Agricultural Sciences, Sweden

A biomass-based carbon tin oxide (SnO₂) composite anode (BC/Sn) was prepared and compared to its pure carbon (BC) form as a candidate for lithium-ion (LIBs) and sodium-ion (NIBs) batteries. The characterization data proved that the SnO2 had a remarkable impact on MC/Sn physicochemical properties, favoring the MC/Sn anode electrochemical performance compared to BC in LIBs and NIBs. For LIBs, MC/Sn anode delivered a specific capacity of 319 mAhg⁻¹ at the end of 120 cycles, while pure carbon delivered only 93.2 mAhg⁻¹ at the end of 120 cycles (at 1C). Moreover, when MC/Sn was subjected to a cycling performance at 0.1C, it exhibited a capacity of 453 mAhg⁻¹ at the end of 120 cycles. When both samples were tested in NIBs, MC/Sn exhibited better cycling stability giving a higher capacity during all cycles compared to pure carbon anode, delivering a capacity of 204 mAhg^-1 at the end of 162 cycles, while pure carbon delivered a capacity of 165 mAhg^-1 at 100mAg^-1.

Weicheng Hua (Ph.D. student)
Norges teknisk-naturvitenskapelige universitet (NTNU), Norway

Ionic liquids (ILs) are a safer electrolyte alternative over conventional electrolytes for Li-ion batteries. Specifically, phosphonium based ILs are investigated due to their large electrochemical stability window, high lithium salt solubility and stable SEI formation. Three different phosphonium ILs (P1112, P1113, P111i4) for application with diatom-SiO2 anodes are reported. The physio-chemical properties were first studied by thermal (TGA) and thermodynamic (DSC) analysis, and an increase in thermal stability with the alkyl group length is found. Cyclic voltammetry results showed that the phosphonium IL electrolytes are stable between within a range between -0.1 V and 4.5 V vs. Li+/Li. To study Li metal stability at the anode side, Li symmetric cells were aged to give insight on the stability of the Li/IL interphase layer. Finally, the ILs outperform conventional liquid electrolyte in galvanostatic tests done at both room temperature and 45°C and P1113 showed the best performance.

Zhichen Ba (Ph.D. student)
Åbo Akademi University, Finland

Solid-state sodium-ion batteries using gel electrolyte with improved safety and high theoretical capacity are considered as the next generation of high-energy-density batteries. However, the inferior interfacial stability and sharp drop in conductivity at low temperatures hinder their practical applications. In this study, a NaTFSI/hydroxyethyl methacrylate polymerizable deep eutectic solvent is used to construct a low-temperature-resistant gel electrolyte by introducing cyanoethyl cellulose network, which aims to promote the dissociation of salts and thus improving the ionic conductivity remarkably (0.66 mS cm-1 at 25 oC). The interface is reinforced after initiating polymerization under UV to prevent sodium dendrites. Furthermore, an extremely wide high thermal stability are proved by low freezing point at -70 oC and non-decomposition temperature at 300 oC. This study provides a broader promise towards safe, low-cost, and high-performance electrolytes in sodium-ion batteries.

Amritha P. Sandra (Ph.D. student)
KTH Royal Institute of Technology, Sweden

The demand for lithium-ion batteries is growing due to the expanding electric vehicle and portable electronics markets. Sustainable and safe battery technologies are essential. Binders, though low in volume, are crucial as they interconnect the active material and current collector, influencing electrode processing. PVDF is commonly used but requires hazardous organic solvents like NMP, which are not eco-friendly. Hence, large-scale aqueous-based processing is crucial to reduce LIB production’s environmental impact. We present colloidal nanostructured chitins from fisheries waste as a fluorine-free, sustainable binder for LIB electrodes. This nanochitin enables aqueous processing with minimal binder content and no need for extra surfactants to disperse hydrophobic materials in water. The electrochemical performance of Gr | Li half-cells was compared with PVDF-based electrodes. Online electrochemical mass spectrometry was used to study binders’ impact on parasitic gas evolution in LIBs.

Hammad Farooq (Ph.D. student)
Norges teknisk-naturvitenskapelige universitet (NTNU), Norway

The growing demand for lithium-ion batteries (LIBs) has significantly strained the primary resources of lithium (Li) and graphite, necessitating efficient recycling of waste LIBs (black mass). Herein, we show that Li can be selectively recycled from a non-pyrolyzed NMC111-type black mass by leaching it with water. The results showed that pH is the dominant factor during Li leaching, and the optimized parameters were 80 °C, 30 min reaction time, and pH 10. It was observed that CLi in the leachate ranges from 100 – 500 mg/L, and to extract this Li, several ion exchange resins were used to study the uptake capacity, selectivity, and the effect of impurities. The results from batch setup showed that Li was efficiently extracted, and later up-concentrated by a factor of 12 – 14. The process is optimized for continuous operation and evaluated with many Li-waters e.g., artificial solution, leachates and flotation water post-graphite recovery thus enabling efficient and scalable Li extraction.

Mie Engelbrecht Jensen (Ph.D. student)
DTU Energy, Denmark

Large quantities of battery waste from electric vehicles will soon build up. Improved recycling technologies are needed. Hydrometallurgical recycling is a more sustainable alternative to pyrometallurgical recycling due to the lower energy consumption. The climate impact of hydrometallurgical recycling depends on chemical consumption as the technology is based on leaching. The initial steps of the transition metal (TM) dissolution at the electrode leachate interface are not understood. Theoretically, a reductant is required for metal dissolution to occur. Experimentally, it is known that up to 40% of the TMs in NMC can be recovered in acid without a reductant.  Computational methods can be used to model electrode leachate interfaces and determine the initial dissolution steps.   Here we apply density functional theory calculations to study leaching processes. Our findings will provide fundamental understanding of battery leaching processes and guide the development of new processes.

Killian Stokes-Rordiguez
SINTEF, Norway

Aqueous processing of transition metal oxide cathodes is highly desirable for reducing processing costs and improving sustainability. If combined with a cobalt-free cathode, such as spinel LNMO, this strategy can significantly reduce the environmental impact of LIBs while providing a high energy cathode for electric vehicle applications. However, aqueous processing of LNMO remains challenging due to pH increases and current collector corrosion. This study investigates the stability of LNMO in water processible polyacrylic acid (PAA) as a function of pH. The pH of PAA was adjusted using Na or Li salts to form NaPAA and LiPAA with pH values ranging from 5 to 8. The binders were evaluated on their pH buffering capabilities during aqueous processing of LNMO electrodes. ICP-MS was used to characterize the amount of transition metal leaching from LNMO at the different binder pHs. The electrochemical performance of the prepared electrodes was evaluated and benchmarked against PVDF cathodes.

Bettina Pilgaard Andersen (Ph.D. / Postdoc)
Aarhus University, Denmark

Rechargeable batteries are widely used in today’s society. To keep up with the demand and be able to meet the requirements of present and future technologies, it is necessary to discover and develop new electrode materials. However, it is also crucial to be able to take full advantage of and improve already existing materials and understand the echanisms taking place during operation of the battery cell. One of these materials is α-Li3V2(PO4)3 which, as a positive electrode, has received a lot of attention due to its high theoretical capacity, good capacity retention, and relatively high ionic conductivity. However, recent studies have shown that it is not only possible to extract the existing three Li-ions in the structure [1], but it should be possible to insert additional Li-ions as well [2-5]. To exploit the full capacity range of the material it is necessary to determine the more exact Li-storage capabilities as earlier studies do not agree about the number of Li-ions possible to store, suggesting between 5 and 9 Li-ions [2-5]. Furthermore, it is necessary to investigate the structural transitions taking place as previous studies have mainly used arguments based on electrochemical measurements [2-5].
In this study, α-Li₃V₂(PO₄)₃ is used in a half cell against Li metal to study the structural evolution at both deep charge and discharge, utilizing techniques as operando powder X-ray diffraction and Rietveld refinements, ex-situ total scattering and pair distribution function analysis, ex-situ X-ray absorption near edge spectroscopy, and void space analysis. Thereby, valuable information about the structural evolution, phase transitions, and evolution of the oxidation state of vanadium is obtained, giving more insight into the capabilities of α-Li₃V₂(PO₄)₃ as an electrode material.

Astrid Holstad Berge (Ph.D. student)
University of Cambridge, United Kingdom

Current battery research focuses on improving and overcoming the remaining challenges facing batteries, namely increasing their longevity, energy density and safety. One strategy is to substitute the lithium conducting liquid electrolyte with a solid electrolyte. Solid electrolyte-based Li-ion batteries can enable energy storage devices with high energy and power densities whilst also being safer than liquid electrolytes.¹
Since it was first synthesised in 2007, Li₇La₃Zr₂O₁₂ (LLZO) has received attention as a promising candidate for solid electrolytes due to its high conductivity and stability against Li metal.² LLZO is a tetragonal Li⁺ conductor which upon doping with a cation forms a cubic structure. The cubic lattice has better connectivity of Li+ sites and a higher number of Li⁺ vacancies, increasing the Li-ion conductivity by two orders of magnitude.³ Despite the dopant atom’s key influence on the conductivity, there is debate in the field regarding the atomic positions of the dopant in the solid electrolyte.
In this study, Al³⁺ doped LLZO (Al_0.36Li_5.92La₃Zr₂O₁₂) was synthesised and the 27Al Nuclear Magnetic Resonace (NMR) signals were recorded showing three aluminium environments in LLZO. Using a Double Quantum Single Quantum NMR experiment, these peaks were identified to be Al doped in a tetragonal (24d) site in LLZO and Al in two impurities, LiAlO₂ and LaAlO₃. Furthermore, Ga³⁺ doped LLZO (Ga_0.2Li_6.3La₃Zr₂O₁₂) was synthesisted and the two 71Ga NMR resonances were identified as Ga³⁺ in LLZO and LiGaO_2.4.
To further investigate LLZO, a mixture of endogenous and exogenous Dynamic Nuclear Polarisation (DNP) NMR was performed. Using a combination of direct 27Al DNP and a 7Li – 27Al D-HMQC DNP experiment, the environment of Al in LLZO and the degradation near LiAlO₂ and LaAlO₃ were explored.

1. J. Janek, W. G. Zeier, Nat Energy 2016, 1, 16141
2. R. Murugan, V. Thangadurai, W. Weppner, Angew. Chem. Int. Ed. 2007, 46 (41), 7778-7781
3. J. Awaka, A. Takashima, K. Kataoka, N. Kijima, Y. Idemoto, J. Akimoto, Chem Lett 2011, 40 (1), 60–62
4. S. Vema, A. H. Berge, S. Nagendran, C. P. Grey, Chemistry of Materials 2023, 35 (22), 9632-9646

Gints Kucinskis (Researcher)
University of Latvia, Latvia

LiNi_xCo_yMn_1-x-yO₂ (NCM) cathodes, especially those with high nickel content, are critical for advancing the energy density of lithium-ion batteries yet face significant challenges in maintaining good cycle life. In this study, we introduce a sustainable ethanol-based wet-chemical method to coat NCM111 cathodes with a thin layer of Al₂O₃, aimed at mitigating surface degradation mechanisms. Beyond studying the coating itself, our study also emphasizes the importance of isolating the benefits of the protective coating from those of re-sintering and surface contaminant removal.
The effects that washing, sintering, and coating have on the electrochemical performance of NCM111 were systematically evaluated. The Al₂O₃-coated NCM111 demonstrated a substantial improvement in cycling stability, retaining 88% of its initial capacity after 500 charge-discharge cycles, compared to 79% for re-sintered and 65% for untreated samples. While sintering alone enhances cycle life by regenerating the material and eliminating residual lithium compounds on the particle surface, the Al₂O₃ coating further augments the electrochemical performance, most likely by helping to maintain the layered structure and inhibiting adverse reactions with the electrolyte.
This study presents a cost-effective, environmentally friendly approach to extend the cycle life of NCM cathodes. This method, combined with doping and microstructural modifications, could significantly advance the cycle life of next-generation lithium-ion batteries, especially when applied on high Ni-content NCM materials.

Acknowledgements. The support of the M-Era.net project “Inert Coatings for Prevention of Ageing of NMC Cathode for Lithium-Ion Batteries” (InCoatBat), Project Reference Number 10341 is acknowledged. Institute of Solid-State Physics, University of Latvia as the Centre of Excellence has received funding from the European Union’s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2.

Esa Hannila (Ph.D. / Postdoc)
University of Oulu, Finland

Energy storage solutions are needed at an ever-growing rate in the modern world. The main driving force is demands for higher efficiency and sustainability for which printing technologies have shown great potential. In this study we use high-speed valve-jetting to fabricate cathodes. Valve-jetting lacks production speed if compared to e.g. screen-printing but offers fast customization and flexibility for production. Due to its modular 5-axis design, it is compatible with a variety of slurries and even three-dimensional structures. The study focuses on the effect of filling strategies by evaluating printed samples through optical and electrochemical battery tests. Based on the results, printed cathodes have similar surface roughness regardless of the filling strategy. However, different strategies have characteristic surface profiles as thicker areas, which could affect the battery performance and lifetime. Thus, process optimization is needed to ensure safe and reliable batteries.

Matthijs Holthuijsen (Ph.D. student)
Beyonder, Norway

This industry PhD project (a collaboration between Beyonder AS and the University of Stavanger) aims to study early-stage solid-electrolyte interphase (SEI) evolution for commercial lithium- and sodium-ion battery chemistries. Raman spectroscopy can be used to study organic and inorganic substances like those found in an SEI, but it generally lacks sensitivity. This problem can be solved by applying nanoparticles to the electrode, a method known as Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy (SHINERS). Gold nanoparticles around 50nm in size resonate with red laser light, strongly boosting the Raman signals of nearby molecules. This signal enhancement is orders of magnitude stronger than signals from the bulk electrolyte, allowing SEI species to be studied with little interference. This method will be used to study the composition of the SEI with different electrolytes and formation protocols, to help predict long-term battery performance at an early stage.

Jonathan Fagerström
Institute for Energy Technology (IFE), Norway

The railway sector is considering the implementation of partially electrified routes, which would involve the use of both electric catenaries for charging and “off-grid” battery propulsion for locomotives. Such a set-up enables multiple system designs for cost-efficient and reliable operation. The purpose of this work was to generate realistic drive cycles for a freight train and analyze how battery lifetime is affected by system design. Two different battery types were included, and the battery capacity was varied to study how different stress factors impact the battery lifetime. Using an empirical battery degradation model, tuned for a power cell of NMC pouch type, it was found that a low-capacity battery pack loses 5% more capacity compared to a high-capacity battery pack. It was also found that 500 return trips reduced the low-capacity pack to 85% of rated capacity. These findings will be compared with degradation results of a cylindrical LFP power cell.

Ali Abo Hamad (Ph.D. student)
Mid Sweden University, Sweden

Silicon-based anodes offer high capacity for lithium-ion batteries (LIBs) but face challenges due to volume expansion. The study introduces a novel approach using urea as a dual etchant for silicon microparticles. This process involves mechanical etching via urea phase transfer within silicon voids and chemical etching induced by urea and ammonia gas. Elevated temperatures trigger urea decomposition, generating ammonia gas and solid by-products. Material characterization confirms the formation of cracks, voids, and pores on silicon microparticles. Two temperature programs (220°C and 400°C) are employed, each addressing solid by-product removal differently. Integrating porous silicon particles into anodes with graphite enhances capacity and cycle stability. With 9% porous Si content, the initial capacity reaches 660 mAh/g, maintained at 520 mAh/g after 150 cycles at 100 mA/g. This research sheds light on dual etching mechanisms with urea, enhancing silicon-based anodes in LIBs.

Nienke Visser (Ph.D. / Postdoc)
Mid Sweden University, Sweden

Silicon is regarded a promising candidate to supplement or substitute graphite as anode material in LIBs, due to its high lithium storage capacity. Its large volumetric change during cycling is problematic, as it causes a significant capacity fade. The use of binary Si alloys, in which Si is combined with active or inactive materials, such as Sn, Al or Fe, can help to increase the stability of the anode material. Although material screenings have shown positive impacts on electrochemical and cyclability performance of binary Si-based anodes, detailed knowledge on the stabilisation mechanisms is lacking.[1] We use physical vapor deposition (PVD) to prepare all solid-state batteries consisting of Si alloys (anode), LiPON (electrolyte) and LCO (cathode). These thin film batteries are ideal for an operando TEM study, with which we aim to probe the mechanism of (de)lithiation of binary Si anodes to better understand their stabilisation mechanism.

[1] J. Power Resources, 520 (2022) 230871

Julia Wind (Researcher)
Institute for Energy Technology (IFE), Norway

Depending on the application, LIBs are normally optimized for either supplying as much power as possible or storing as much energy as possible. A power optimized cell typically has lower energy density and thinner electrodes, compared to an energy optimized cell with higher energy density and thicker electrodes. However, increased electrode thickness leads to several challenges and affects cell performance and ageing characteristics.
In this study we aim to develop a fundamental understanding of electrode performance and limitations through the evaluation of high-energy and high-power electrodes from state-of-the-art LIBs. For this purpose, we selected two large-scale commercial pouch cells with similar geometry, chemistry, and capacity: one optimized for power and one for energy.
Both cell types were tested at different temperatures, currents and SoCs. Cell-tear-down analysis revealed differences in battery design. The results were used to parameterize a P2D electrochemical model.

Helene Lillevestre Langli
Norges teknisk-naturvitenskapelige universitet (NTNU), Norway

Kristian O. Sylvester-Hvid
DTU Energy, Denmark

Weldejewergis Kidanu (Postdoc)
Norges teknisk-naturvitenskapelige universitet (NTNU), Norway

Due to its electrochemical stability, ionic conductivity and passivation of the Al current collector, state-of-the-art LiBs mainly use LiPF6 as an electrolyte salt. However, its thermal instability, sensitivity to trace amounts of moisture and the consequent formation of HF need to be addressed with alternative salts such as LiFSI.  On the other hand, during LiB cell manufacturing, 80~95% of the energy consumption occurs in electrode drying and dry room conditioning. Hence, LiFSI-based LiBs that can tolerate certain levels of moisture are of interest to reduce the energy consumption.
Herein, effect of moisture on LiFSI based NMC622/Li and graphite/Li half and NMC622/graphite full cells  were investigated, and surface chemistry and morphology of cycled electrodes were characterized with XPS and SEM. It was found that ~1000 ppm H2O slightly improves the capacity retention of the NMC622 half cells; however, severely degrades the graphite half-cell and NMC622/graphite full cells.