亲锂且分布均匀的富锂合金制备及其在高倍率金属锂电池应用

Preparation of Lithiophilic Li-Rich Alloy Anode with Uniformly Distribution for High-Rate Lithium Metal Batteries

摘要:

锂金属电池（LMBs）作为最具前景的下一代储能系统，其实际应用因严重的枝晶问题受阻。制约长循环寿命与高倍率性能的关键因素，在于亲锂位点匮乏及分布不均。本研究报道了一种通过熔融锂与金属反应生成富锂的锂合金，该合金Li9Al4具有强的亲锂性，且在基体均匀分散。这种结构提供了丰富且均匀的亲锂位点，实现锂的均匀沉积/剥离、抑制枝晶的形成。因此，所得对称电池可稳定循环超过1200 h，过电位低至56 mV，所组装全电池在5 C下循环400 次后容量保持率仍达93.2%。该工作为高倍率锂金属电池的开发提供了新的思路。

Abstract:

Lithium metal batteries (LMBs) are regarded as one of the most promising energy-storage systems for next-generation, but their practical application is still hindered by severe lithium dendrite growth. The key factors limiting long cycle life and high-rate performance are the scarcity of lithiophilic sites and their nonuniform distribution. Herein, we report a Li-rich lithium alloy formed via a simple molten-lithium alloying reaction, featuring uniformly dispersed Li9Al4 with strong lithiophilicity. This architecture provides abundant and uniformly distributed lithiophilic sites, ensuring homogeneous lithium plating/stripping and suppressing dendrite formation. As a result, the symmetric cells based on the anode deliver stable cycling for over 1200 h with a low overpotential of 56 mV, and the assembled full cells based on the anode maintain a capacity retention of 93.2% even after 400 cycles at 5 C, offering a scalable pathway toward high-rate lithium metal batteries.