Solid-State Batteries: Innovations, Promising Start-Ups, & Future Roadmap

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Revolutionizing Automotive Energy Storage: Investigating the integration of Cell-to-Pack (CTP) and Cell-to-Chassis (CTC) concepts for heightened energy densities and cost efficiency, coupled with a heightened emphasis on mixed cell chemistry concepts both on pack and cell level. Next-gen technology development: Navigating fluctuating raw material prices with Sodium-Ion Batteries (SIB) and Embracing Innovations in Anode Engineering and (Semi-)Solid-State technology for diverse applications including EV business and beyond. Diversification of cell manufacturer’s product portfolio: Increasing significance of market segmentation addressing the variety of needs for applications such as Bus, Truck, Off-Highway and ESS, and the standard EV business.

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Current lithium-/sodium-ion batteries (LIBs/SIBs) are unable to meet the rapidly-growing energy demand, and one of the major reasons originates from the limited specific capacity of carbonaceous anode materials. Therefore, manufacturers and researchers are shifting their focus towards materials with greater specific capacities. Among these materials, Sn has garnered increasing attention owing to its outstanding specific capacity in both LIBs (994 mAh/g) and SIBs (847 mAh/g) and excellent compatibility in both battery chemistries, showing great potential as one of the next-generation anode candidates.Nonetheless, its commercial use is significantly impeded by the capacity degradation during cycling. This degradation primarily results from the anode pulverization, triggered by the huge volume changes during charging and discharging. To address this problem, a novel nanostructured free-standing Sn-based ribbon is developed via a fast, one-step and solvent-free melt spinning process, and can be directly applied as anode, without the need of conventional electrode making and use of current collector. The anode pulverization issue has been significantly mitigated by the well-designed nanostructures and alloy phases, as well as other effective optimization strategies. As a result, the ribbon anode has been demonstrated in LIBs and SIBs and shown substantial improvements in specific capacity, cycle life, and rate capabilities.
In this talk, we will provide a brief overview of the melt spinning technique and some of our recent work in the development of ribbon anodes. We hope these findings can offer new insights into developing “next-generation” high-performance alloy-based anode materials.

Advanced sodium ion batteries have already achieved energy densities competitive with lithium ion, however, despite promises of its improved safety properties, its safety metrics have not yet been clearly defined. This session will comprehensively describe the root causes of battery thermal runaway, compare the safety abuse data sets of various sodium ion battery chemistries. It will also cover recent trends in the sodium battery markets and how the sodium supply chain can alleviate today's critical material bottlenecks faced by the industry.

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The need for more ecological and sustainable production technologies is a general demand for competitive battery manufacturing factories in the future. The energy consumption and carbon dioxide emissions are cost-driving factors and at the same time have high increasing social impacts. Solutions for making electrode production greener can be realized by avoiding or replacing toxic and harmful materials, e.g. by aqueous processing. Also less solvent requiring processes may lead to less extensive drying efforts. Screen-printing technology for electrode manufacturing combines both environmental benefits and enables for thick film electrode production with high areal capacities especially for high energy cells (up to 5…8 mAh/cm 2 ). In this work it will be shown that the solvent amount can be decreased by about 20% by processing of highly filled pastes. In addition, it is possible to enable a multilayer printing and therefore sequential and fast drying as well as near-net-shape printing leading to less waste upon production. The thickness and high areal capacity of the printed coatings lead to new design aspects of the electrode structure affecting full cell performance. Some insights will be given with regard to current-rate capability, useable capacity, porosity and efficiency of ion- exchange pathways. The screen-printing process is a scalable and established series production technology. The high accuracy, energy efficiency and low emissions are strongly in line with the goals of green production.

The need for more ecological and sustainable production technologies is a general demand for competitive battery manufacturing factories in the future. The energy consumption and carbon dioxide emissions are cost-driving factors and at the same time have high increasing social impacts. Solutions for making electrode production greener can be realized by avoiding or replacing toxic and harmful materials, e.g. by aqueous processing. Also less solvent requiring processes may lead to less extensive drying efforts. Screen-printing technology for electrode manufacturing combines both environmental benefits and enables for thick film electrode production with high areal capacities especially for high energy cells (up to 5…8 mAh/cm 2 ). In this work it will be shown that the solvent amount can be decreased by about 20% by processing of highly filled pastes. In addition, it is possible to enable a multilayer printing and therefore sequential and fast drying as well as near-net-shape printing leading to less waste upon production. The thickness and high areal capacity of the printed coatings lead to new design aspects of the electrode structure affecting full cell performance. Some insights will be given with regard to current-rate capability, useable capacity, porosity and efficiency of ion- exchange pathways. The screen-printing process is a scalable and established series production technology. The high accuracy, energy efficiency and low emissions are strongly in line with the goals of green production.

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For decades the manufacturing process of batteries and its components has shown only incremental improvements to cost efficiency, energy efficiency and low yield rates. It requires a significant technology step to harvest new efficiencies in capex, opex, sustainability and new battery storage solutions. Advances in battery material science combined with experience from the semiconductor manufacturing industry now enable significant progress in electrode manufacturing, new battery concepts, solid state batteries and safer energy storage.

Several technology players have been attempting to establish and scale a dry electrode manufacturing process that overcomes the high energy demand, low reliability, low flexibility, high carbon footprint and use of toxic materials of today’s wet coating processes. The biggest advances though, are only possible by combining material preprocessing and new high speed additive manufacturing. Dry electrode printing reduces energy consumption and carbon footprint, eliminates all use of toxins and forever chemicals while delivering full scalability and high volume cost efficiencies. Dry printing of electrodes is the first step to printing complete batteries, in arbitrary shape and form, including SSB materials, eliminating metal foils and integrate inherent safety features – all at competitive high volume efficiency.

For decades the manufacturing process of batteries and its components has shown only incremental improvements to cost efficiency, energy efficiency and low yield rates. It requires a significant technology step to harvest new efficiencies in capex, opex, sustainability and new battery storage solutions. Advances in battery material science combined with experience from the semiconductor manufacturing industry now enable significant progress in electrode manufacturing, new battery concepts, solid state batteries and safer energy storage.

Several technology players have been attempting to establish and scale a dry electrode manufacturing process that overcomes the high energy demand, low reliability, low flexibility, high carbon footprint and use of toxic materials of today’s wet coating processes. The biggest advances though, are only possible by combining material preprocessing and new high speed additive manufacturing. Dry electrode printing reduces energy consumption and carbon footprint, eliminates all use of toxins and forever chemicals while delivering full scalability and high volume cost efficiencies. Dry printing of electrodes is the first step to printing complete batteries, in arbitrary shape and form, including SSB materials, eliminating metal foils and integrate inherent safety features – all at competitive high volume efficiency.

The development of cost-effective, high-performance battery manufacturing technologies is essential to support the U.S. electric vehicle, energy storage, and consumer electronics markets. Shifting from wet to dry processing for battery electrodes
promises to lower capital costs, energy usage, and environmental impact. This presentation explores our work on powder-based additive manufacturing techniques to produce cathode and solid electrolyte films without solvents. Using methods like selective laser melting and cold spray, these energy-efficient processes minimize material waste while achieving production speeds comparable to conventional slurry casting. I will discuss the additive manufacturing processes, the critical factors influencing film quality, and cell performance in comparison to traditional slurry-based methods. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

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Solid-state batteries offer the promise of improved energy density and safety compared to lithium-ion batteries. However, the electro-chemo-mechanical evolution of materials at solid-solid electrochemical interfaces is different than at solid/liquid interfaces, and contact evolution in particular plays a critical role in determining the behavior of solid-state batteries. Using X-ray tomography, cryo-FIB, and finite-element modeling, we show that anode-free solid-state lithium metal batteries are intrinsically limited by current concentrations at the end of stripping due to localized lithium depletion. This causes accelerated short circuiting compared to lithium-excess cells. Based on these results, the beneficial influence of metallic interfacial layers on controlling lithium evolution and mitigating contact loss from localized lithium depletion will be discussed. We also show that alloy anodes in solid-state batteries can exhibit improved interfacial stability and enhanced cyclability compared to Li-ion batteries. A comprehensive study on 12 alloy materials shows that lithium trapping is a key limitation for most materials. Further characterization of alloy anodes reveals the dynamic nature of interfacial fracture during reaction processes. Taken together, these findings show the importance of controlling chemo-mechanics and interfaces in solid-state batteries for improved energy storage capabilities.

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Conventional lithium-ion batteries utilizing organic electrolyte suffer severely from several drawbacks associated to the poor electrochemical stability at higher potentials, high volatility and flammability of electrolyte components as well as poor performance at lower temperatures. To overcome these issues we developed a novel purely inorganic electrolyte consisting of sulfur dioxide as a solvent and a proprietary conductive salt. [1,2] This electrolyte formulation shows superior stability towards potentials of up to 5V together with exceptional ionic conductivity exceeding organic electrolyte by up to an order of magnitude. Throughout this presentation we will discuss in detail the basic properties and electrochemical performance of our SO2-based electrolytes in comparison to state of the art organic electrolyte. Extensive research efforts of the last few years have led to a unique electrolyte system, which is capable to withstand electrolyte decomposition beyond a potential of 5V. The larger potential window allows for higher average discharge potentials and significantly increased capacities. For NMC, for instance, a capacity increase of 20% is possible, which not only enhances cell energy but may also reduce cost due to more efficient cathode utilization. 21700 cells manufactured with our pilot-scale manufacturing equipment already achieved energy densities as high as 310 Whkg-1 with ordinary NMC/graphite cell chemistry. Recently, we have shown that our cells not only may be cycled for hundreds of cycles at 4.6 V but also demonstrate exceptional charge/discharge characteristics at temperatures as low as -40 °C. Our cells also passed all tests associated to UN38.3 which paves the way towards commercial applications. Our technology may be understood as a drop in solution for large scale battery cell manufacturing. Only small modifications with regard to electrolyte handling and filling have to be made by maintaining all other cell manufacturing processes such as electrode coating and cell assembly. This together with the prospect of proven compatibility with future electrode materials such as LMR, LNMO, LFMP, Silicon or lithium metal makes our technology highly adaptable and future proof.

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The global acceleration towards sustainable energy has driven the need for low-cost, de-carbonized battery manufacturing processes with differentiating product performances. AM Batteries unique dry electrode manufacturing technology aims to deliver on these critical challenges and elevate battery production and performance globally. Our liquid-free battery electrode manufacturing process entails 3 key steps: dry mixing, dry deposition, and mechanical compression. In this talk, we will explain our technology and highlight our achievements and manufacturing advantages over other electrode process options.

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I will discuss a general design strategy for achieving one-dimensional (1D), high- performance polymer solid-state ion conductors through molecular channel engineering, which we demonstrate via Cu 2+ -coordination of cellulose nanofibrils. The cellulose nanofibrils by themselves are not ionic conductive; however, by opening the molecular channels between the cellulose chains through Cu 2+ coordination we are able to achieve a Li-ion conductivity. This improved conductivity is enabled by a unique Li + hopping mechanism that is decoupled from the polymer segmental motion. Also benefitted from such decoupling, the cellulose-based ion conductor demonstrates multiple advantages, including a high transference number (0.78 vs.0.2–0.5 in other polymers 2 ), low activation energy (0.19 eV), and a wide electrochemical stability window (4.5 V) that accommodate both Li metal anode and high-voltage cathodes. Furthermore, we demonstrate this 1D ion conductor not only as a thin, high-conductivity solid-state electrolyte but also as an effective ion-conducting additive for the solid cathode, providing continuous ion transport pathways with a low percolation threshold (Nature, Oct 22).

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Li-ion batteries containing conventional cathodes are unable to meet projected energy demands due to overreliance on critical resources—namely Co and Ni. Disordered rocksalt (DRX) materials represent a promising class of next-generation cathodes due to their high specific energy (>700 Wh/kg) and compatibility with earth-abundant transition metals (e.g., Mn and Ti). Despite these promising attributes, a major limitation of DRX cathodes is the lack of scalable synthesis platforms which enable fine tuning of the material’s structure and Performance. To address this issue, the present study reports the synthesis and characterization of Mn-based DRX oxyfluorides prepared through a scalable two-step route involving: (i) a solution-based combustion reaction to prepare a transition metal oxide precursor, followed by (ii) a high temperature reaction with lithiation/fluorination agents. Overall, the approach yields high purity DRX powders which can be prepared at lower temperatures and over shorter timeframes (e.g., 800 °C and 1 h) compared to conventional solid-state processes. Interestingly, these findings demonstrate that adding LiF to the oxide precursor is critical to facilitate DRX phase formation during the second heating step. These Mn-based DRX cathodes exhibit stable cycling performance with reversible capacities up to ~215 mAh/g in Li metal half cells. This presentation will discuss recent findings for DRX cathodes produced through this two-step reaction route. More specifically, effects of precursor selection and annealing profile on the reaction pathway and electrochemical performance will be highlighted. Overall, these results illustrate the merits and opportunities for scalable combustion reactions to produce Co/Ni-free DRX cathodes.

This talk will cover exciting new results from Stratus Materials showing the performance of our next generation of cathode active materials. We will show how enhanced processing innovations result in materials approaching or exceeding 1000 Wh/kg at a materials level that have excellent performance in a range of use cases. Specifically, data showing that this material is stable in full cells for well over 1000 cycles will be disclosed. Other key metrics such as rate capability, fast charge capability, and manufacturability, and performance in thick-format electrodes will also be discussed. We will also explore the pack-level advantages of using this material using both safety and techno-economic assessments; pack-level energy densities that far exceed those of packs that use LFP and NMC cells are possible due to the energy densities and thermal performance attributes attained. Data from cells up to 20Ah in size will be shared.

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Iron-chromium flow batteries offer a promising, safe, cost-effective, and scalable solution for long-duration energy storage due to the abundance and low cost of their core materials. However, traditional iron-chromium systems have faced challenges related to low efficiency, limited power density, and issues arising from corrosive acidic electrolytes. This presentation explores recent advancements in iron-chromium flow battery technology achieved through the incorporation of organic chelates into the electrolyte. These chelates stabilize iron and chromium ions, allowing the battery to operate at neutral pH, which enhances safety by reducing corrosiveness and eliminating flammable materials. This shift also significantly improves performance metrics, increasing the cell voltage to approximately 1.6 volts—over 50% higher than conventional iron-chromium batteries and about 15% higher than vanadium flow batteries—leading to higher power density and improved round-trip efficiency. The compatibility of this advanced electrolyte with existing flow battery components facilitates rapid scaling and deployment using standard manufacturing processes. Environmental benefits, such as low chemical toxicity and ease of recycling, will be addressed, and upcoming pilot projects will illustrate the practical applications and effectiveness of these innovations in real-world settings.