A thin 3D alloy-type anode enabled by sluggish thermodynamics for spring-free Lithium metal batteries

Lithium metal batteries (LMBs) offer a promising solution to next-generation energy devices. Yet, the low coulombic efficiency (CE) issue compromises the battery performance, and lithium metal's low utilization causes a waste of resources. Herein, we design a novel thin Li/LiNi₃@NF alloy-type anode by sluggish thermodynamics. With negative Gibbs free energy and a low nickel composition phase, the Li/LiNi₃@NF anode is simultaneously achieved, acting as both anode and spring in spring-free LMBs (SFLMBs). Such SFLMBs exhibit lower volume and mass compared to conventional cells. Moreover, the Li/LiNi₃@NF anode demonstrates hierarchy electrochemistry at the stripping/plating process, showcasing a low 16 mV voltage hysteresis. When coupled with LiFePO₄ (LFP) cathode, the SFLMB with Li/LiNi₃@NF retains 86.4 % capacity for 300 cycles at a 1C rate.