All-solid-state batteries with metallic lithium (Li_BCC) anode and solid electrolyte (SE) are under active development. However, an unstable SE/Li_BCC interface due to electrochemical and mechanical instabilities hinders their operation. Herein, an ultra-thin nanoporous mixed ionic and electronic conductor (MIEC) interlayer (≈3.25 µm), which regulates Li_BCC deposition and stripping, serving as a 3D scaffold for Li⁰ ad-atom formation, Li_BCC nucleation, and long-range transport of ions and electrons at SE/Li_BCC interface is demonstrated. Consisting of lithium silicide and carbon nanotubes, the MIEC interlayer is thermodynamically stable against Li_BCC and highly lithiophilic. Moreover, its nanopores (<100 nm) confine the deposited Li_BCC to the size regime where Li_BCC exhibits “smaller is much softer” size-dependent plasticity governed by diffusive deformation mechanisms. The Li_BCC thus remains soft enough not to mechanically penetrate SE in contact. Upon further plating, Li_BCC grows in between the current collector and the MIEC interlayer, not directly contacting the SE. As a result, a full-cell having Li_3.75Si-CNT/Li_BCC foil as an anode and LiNi_0.8Co_0.1Mn_0.1O₂ as a cathode displays a high specific capacity of 207.8 mAh g⁻¹, 92.0% initial Coulombic efficiency, 88.9% capacity retention after 200 cycles (Coulombic efficiency reaches 99.9% after tens of cycles), and excellent rate capability (76% at 5 C).

中文翻译：

---

用于固态锂金属电池的超薄锂硅化物夹层

_{具有金属锂 (Li BCC} ) 阳极和固体电解质 (SE)的全固态电池正在积极开发中。然而，由于电化学和机械不稳定性导致不稳定的 SE/Li _{BCC界面阻碍了它们的运行。}在此，超薄纳米多孔混合离子和电子导体 (MIEC) 夹层 (≈3.25 µm)，调节 Li _BCC沉积和剥离，作为 3D 支架用于 Li ⁰吸附原子形成、Li _BCC成核和长-展示了SE/Li _{BCC界面处离子和电子的范围传输。}MIEC 中间层由硅化锂和碳纳米管组成，对 Li _{BCC具有热力学稳定性}和高度亲锂。此外，它的纳米孔（<100 nm）将沉积的 Li _BCC限制在尺寸范围内，其中 Li _BCC表现出“越小越软”的尺寸依赖性塑性，由扩散变形机制控制。因此， Li _BCC保持足够柔软，不会在接触时机械地穿透 SE。进一步电镀后，Li _BCC在集电器和 MIEC 夹层之间生长，不直接接触 SE。因此，具有 Li _3.75 Si-CNT/Li _BCC箔作为阳极和 LiNi _0.8 Co _0.1 Mn _0.1 O ₂作为阴极的全电池显示出 207.8 mAh g 的高比容量⁻¹，初始库仑效率92.0%，200次循环后容量保持率88.9%（数十次循环后库仑效率达到99.9%），倍率性能优异（5 C时为76%）。