A dimensionally stable lithium alloy based composite electrode for lithium metal batteries

Lithium (Li) metal is regarded as the most promising anode material for next-generation secondary batteries due to its high theoretical specific capacity and low potential. However, the huge volume change and uncontrollable dendrites growth lead to its structural instability during charge/discharge processes. Herein, a lithium alloy -based composite (Li-Sn-Bi) is fabricated for the first time, by fusing Li metal and low melting Sn-Bi eutectic alloy to address the structural change of Li electrodes. In this composite electrode, Li3Bi alloy exhibits a skeleton structure that can alleviate dimensional change of the electrode, meanwhile Li-Sn alloys (Li(22)Sn(5 )and Li5Sn2) are embedded in the Li3Bi skeleton that uniform Li plating owing to their low lithium mass-transfer barriers. Thus, the Li-Sn-Bi electrode can preserve its structural integrity during the redox process by combining the respective role of each alloy. Notably, the lifespan of the symmetric battery with Li-Sn-Bi electrode exceeds 4000 h under a fixed capacity of 3 mAh cm(-2) and sustains 2000 cycles at a high current density of 30 mA cm(-2). This work provides a facile method to fabricate dimensionally stable Li composite electrodes for high-energy-density secondary lithium batteries.

Automated summary

In this study, a lithium alloy-based composite electrode was successfully fabricated, which exhibited structural stability and improved performance in secondary lithium batteries.