Solid-state batteries (SSBs), in which all components exist in solid states, are garnering considerable interest in energy storage applications due to their potentially high energy and power, as well as good safety. One of the major challenges in SSB development is the loss of contact between electrode and electrolyte particles, leading to poor cyclability. Consequently, high external pressure, typically exceeding 100 MPa, is often applied in the cycling experiments of SSBs. However, this approach is incompatible with real-world applications where low operating pressure is imperative. Now, Jean-Marie Tarascon and colleagues in France engineer a cathode–electrolyte composite, mainly consisting of a mixed chloride-bromide halide complex (Li₃YBr₂Cl₄) and a nickel-manganese-cobalt oxide (LiNi_0.6Mn_0.2Co_0.2O₂). They demonstrate stable cycling against lithium-based anodes near atmospheric pressure.

The researchers show that Li₃YBr₂Cl₄ exhibits improved mechanical ductility compared to conventional solid electrolytes. This property helps mitigate issues related to inadequate contact with the cathode material. However, the composite remains incompatible with lithium anodes due to its reduction instability. To tackle this problem, Tarascon and team incorporate a protective layer made of an argyrodite compound (a typical solid electrolyte), resulting in a dual-electrolyte cell. They report cycling down to 0.1 MPa against a LiIn alloy and 0.2 MPa against a Li metal anode, with limited capacity loss. While demonstrating the potential of these cells for low-pressure applications, the researchers also discuss the limitations of their system in terms of rate capability and long-term degradation.

固态电池（SSB）的所有组件均以固态存在，由于其潜在的高能量和功率以及良好的安全性，在储能应用中引起了相当大的兴趣。SSB开发的主要挑战之一是电极和电解质颗粒之间失去接触，导致循环性能差。因此，SSB 的循环实验中经常施加高外部压力，通常超过 100 MPa。然而，这种方法与必须低工作压力的实际应用不兼容。现在，Jean-Marie Tarascon 和法国的同事设计了一种阴极电解质复合材料，主要由混合氯化物-溴化物卤化物络合物 (Li ₃ YBr ₂ Cl ₄ ) 和镍-锰-钴氧化物 (LiNi _0.6 Mn _0.2 Co _{0.2 )}组成。氧₂）。他们展示了在接近大气压的情况下对锂基阳极的稳定循环。

研究人员表明，与传统固体电解质相比， Li ₃ YBr ₂ Cl _{4表现出更高的机械延展性。}这一特性有助于缓解与阴极材料接触不充分相关的问题。然而，由于其还原不稳定性，该复合材料仍然与锂阳极不相容。为了解决这个问题，Tarascon 和团队采用了由银汞矿化合物（一种典型的固体电解质）制成的保护层，从而形成了双电解质电池。他们报告称，对于 LiIn 合金，循环压力降至 0.1 MPa，对于锂金属阳极，循环压力降至 0.2 MPa，容量损失有限。在展示这些电池在低压应用中的潜力的同时，研究人员还讨论了其系统在速率能力和长期退化方面的局限性。