Lateral growth of Lithium dendrite enforced by 3D porous Core@Shell-Cu@Li3N protective layer toward Long-Life Lithium metal anode

Li metal is promising as the anode for next -generation Li -ion batteries; however, uncontrollable dendrite growth and severe side reactions between the Li metal and electrolyte greatly restrict its commercialization. Here, a 3D porous protective layer constructed by core@shell-Cu@Li3N particles is developed to solve the above issues. This protective layer is easily prepared just by one-step dip coating in Cu(NO3)2/N-methyl-2-pyrrolidone (NMP) solution. Due to rapid Li+ transport and good wettability of the protective layer, it effectively modulates Li+ flux and thus homogenizes Li deposition. More importantly, as confirmed by both the experimental results and phasefield simulations, the 3D porous protective layer enforces the Li dendrite to laterally grow to form an interconnected network, which causes that the subsequent Li deposition is constrained and filled in the inner space rather than savage growth. Therefore, both the symmetric battery and full cell constructed by the protected Li electrode displays much longer lifespan than the one with bare Li even in unstable liquid carbonate electrolyte. Also, this protective layer is demonstrated to be compatible with Li1+xAlxTi2-x (PO4)3 (LATP) solid-state electrolyte by suppressing the side reactions. This work paves a new and facile strategy for developing highperformance Li metal anode.