Lithium alanates exhibit high theoretical specific capacities and appropriate lithiation/delithiation potentials, but suffer from poor reversibility, cycling stability, and rate capability due to their sluggish kinetics and extensive side reactions. Herein, a novel and facile solid‐state prelithiation approach is proposed to in situ prepare a Li₃AlH₆‐Al nanocomposite from a short‐circuited electrochemical reaction between LiAlH₄ and Li with the help of fast electron and Li‐ion conductors (C and P6₃mc LiBH₄). This nanocomposite consists of dispersive Al nanograins and an amorphous Li₃AlH₆ matrix, which enables superior electrochemical performance in solid‐state cells, as much higher specific capacity (2266 mAh g⁻¹), Coulombic efficiency (88%), cycling stability (71% retention in the 100th cycle), and rate capability (1429 mAh g⁻¹ at 1 A g⁻¹) are achieved. In addition, this nanocomposite works well in the solid‐state full cell with LiCoO₂ cathode, demonstrating its promising application prospects. Mechanism analysis reveals that the dispersive Al nanograins and amorphous Li₃AlH₆ matrix can dramatically enhance the lithiation and delithiation kinetics without side reactions, which is mainly responsible for the excellent overall performance. Moreover, this solid‐state prelithiation approach is general and can also be applied to other Li‐poor electrode materials for further modification of their electrochemical behavior.

中文翻译：

---

固态预锂化可为固态电池实现高性能的Li-Al-H阳极

铝酸锂显示出高的理论比容量和合适的锂化/脱锂电位，但是由于其缓慢的动力学和广泛的副反应而具有差的可逆性，循环稳定性和速率能力。本文提出了一种新颖且简便的固态预锂化方法，该方法是利用快速电子和锂离子导体（LiC）在LiAlH ₄和Li之间的短路电化学反应中原位制备Li ₃ AlH ₆ -Al纳米复合材料。和P6 ₃ mc LiBH ₄）。该纳米复合材料由分散的Al纳米颗粒和无定形Li ₃ AlH _6组成基质，可在固态电池中实现出色的电化学性能，更高的比容量（2266 mAh g ^-1），库仑效率（88％），循环稳定性（在第100个循环中保留71％）和速率能力（1429）获得了在1 A g ^-1时的mAh g ^-1）。此外，这种纳米复合材料在带有LiCoO ₂阴极的固态全电池中也能很好地工作，证明了其广阔的应用前景。机理分析表明，分散的Al纳米颗粒和无定形的Li ₃ AlH ₆基体可以显着提高锂化和脱锂动力学，而无副反应，这主要归因于出色的整体性能。此外，这种固态预锂化方法是通用的，也可以应用于其他贫锂电极材料，以进一步改变其电化学性能。