Lignin-Derived Holey, Layered, and Thermally Conductive 3D Scaffold for Lithium Dendrite Suppression

Lithium (Li) metal anodes are considered as the holy grail of rechargeable Li batteries. However, the practical utilization of Li metal is challenging because of the dendrite formation issue and drastic volume expansion. Herein, for the first time, through the incorporation of thermally conductive material boron nitride (BN), the Li metal anode is stabilized by improving heat dissipation and charge transfer in a holey and layered structure. Ligninsulfonate, due to its amphiphilicity, is used to in situ exfoliate bulky BN into nanosheets. Through the freeze-casting method, a layered and holey structure is formed, where the as-exfoliated BN nanosheets can well manage thermal distribution and lead to a uniform deposition of Li. Due to the enhanced thermal dissipation and charge transference, this novel Li anode exhibited a high Coulombic efficiency and a long cycle life at a high current density of 4 mAcm(-2). And the formation of Li dendrite is successfully suppressed during plating/stripping. In a full cell where LiFePO4 composite was used as the cathode, a high capacity of 90 mAh g(-1) was achieved at 10 C with a high capacity retention of 92% after 1800 cycles.