The shield-like nano-sized Si3N4 derivatives to defend against the attack of lithium dendrites

The unrestrained Li dendrite growth impedes the performance of Li metal batteries (LMBs) and brings safety concerns. To mitigate the unfavorable effect of Li dendrites, in this work, a shield-like artificial interlayer composed of Si 3 N 4 is employed to achieve the desirable electrochemical performance of LMBs. The Si 3 N 4 -based interlayer can in-situ electrochemically react with Li to generate inorganic Li 3 N and Li x Si alloys: the former with high ionic conductivity can effectively enhance the Li + transference, while the latter with reversibility for Li + insertion/deinsertion can act as Li + reservoir to modulate Li + platting/stripping. Thus, the Si 3 N 4 -derived compound shield effectively defends against the attack of Li dendrites and suppresses their growth, with which the Li||Li cells can cycle at 1 mA cm −2 (1 mAh cm −2 ) up to 500 h and the LiFePO 4 (LFP) ||Li batteries can operate 400 cycles at 1C with 91.5 % capacity retention.