Lithium Battery Chemistry — Part 2

Mixing electroactive materials, solid-state electrolytes, and conductive carbon to fabricate composite electrodes is the most practiced but least understood process in all-solid-state batteries. We report on universal halide segregation at interfaces across various halogen-containing solid-state electrolytes and a family of high-energy chalcogen cathodes enabled by mechanochemical reaction during ultrahigh-speed mixing. Bulk and interface characterizations show that the in situ segregated lithium halide interfacial layers substantially boost effective ion transport and suppress the volume change of bulk chalcogen cathodes. Various all-solid-state lithium-chalcogen cells demonstrate utilization close to 100% and extraordinary cycling stability at commercial-level areal capacities.

Despite significant promise, widespread adoption of sulfide solid-state electrolytes (SSEs) is hindered by processability in manufacturing environments and lifetime/performance limitations due to (electro)chemical instability. We have developed an approach where ultrathin (= 1 nm) coatings stabilize sulfide SSE powders to aggressively oxidizing atmospheres while significantly improving electrochemical performance. This scalable approach (up to 100 g/batch achieved) enables a new framework for accelerating integration of sulfide SSEs into next-generation solid-state batteries.

This presentation will discuss recent advances in the design of molecular, liquid, and solid‑state electrolytes aimed at enabling high‑voltage lithium batteries with improved safety, stability, and energy density. The talk will highlight strategies to control ion solvation, engineer stable electrode–electrolyte interphases, and mitigate dendrite formation in lithium metal cells. Examples from recent research will illustrate how electrolyte chemistry (e.g. dinitriles, sulfones, ethers) can unlock the performance of next‑generation high‑voltage cathodes and lithium metal anodes.

Battery development calls for tools that will increase the pace of research. The Advanced Electrolyte Model (AEM) is such a tool that is both fast and accurate, owing to its chemical physics platform that covers broad ranges of solvent composition, salt concentration, and temperature. AEM generates over 100 property metrics per run, with typical runs taking less than five seconds to complete. Complex multi-solvent electrolytes can be optimized through AEM using more than a dozen optimization parameters.

LMR materials historically exhibit persistent voltage fade, and require tailored electrolytes. Stratus Materials has developed an efficient and low-cost processing route that creates crystallographically stable cobalt-free LMR, called LXMO. Data will be disclosed showing that LXMO-based large-format cells (20Ah and larger) can exhibit energies of over 700 Wh/l, and cycle-life stability of over 2000 cycles.  Lower energy density versions can compete economically with LFP cells in stationary use cases.

CEA’s battery facilities provide a unique framework for scaling up innovative technologies. The battery prototyping and processing laboratory can produce electrodes from small-format to industry-relevant sizes. This integrated approach allows the evaluation of electrochemical performance, but also the assessment of material processability, slurry formulation, and electrode manufacturing compatibility. The value of this scale-up strategy will be illustrated through CEA’s industrial collaboration with TokaiCobex-Savoie, a French producer of synthetic graphite grades.

This talk presents the charge-discharge cycling performance of ZnNi rechargeable batteries using a new technology to suppress non-uniform reaction distribution of the anode which is the main reason of zinc dendrite generation and growth. The technology provides an excellent rechargeability for thousands of cycles without internal short circuit and capacity loss.