3D Artificial Electron and Ion Conductive Pathway Enabled by MgH2 Nanoparticles Supported on g-C3N4 Towards Dendrite-Free Li Metal Anode

Li metal anode is considered as one of the most promising candidates for next-generation batteries due to its high energy density. The undesired growth of Li dendrites and infinite volume change, however, hinders its practical application. Herein, a 3D structured Li metal anode featured with uniform electron and Li ion conductive pathway is fabricated through the favorable reaction between MgH 2 that are uniformly distributed on g-C 3 N 4 and molten Li. The thus-formed lithiophilic LiMg alloys under the structural support of lithiophilc g-C 3 N 4 could synergistically lower the nucleation barrier of Li plating and hence promote the uniform Li deposition process. Simultaneously, the high Li ion conductivity of thus-formed both LiH and Li 3 N resulting from the reaction between molten Li and MgH 2 and g-C 3 N 4 , respectively, facilitates fast Li ion transportation kinetics along their surfaces towards favorable Li deposition on the surface of g-C 3 N 4 . Consequently, the thus-fabricated Li metal anode with a high specific capacity of 3511 mA h g −1 delivers a long cycling life of over 500 h at 3 mA cm −2 under 3 mA h cm −2 . Impressively, upon coupling this anode with commercial LFP cathode, the thus-assembled full cells deliver a specific capacity of 145 mA h g −1 after 450 cycles at 1 C.