Regulation of Lithium Nucleation by Designing a Biomimetic Carbon Frame for Super Compact and Non-Expanding Lithium Metal Anode

Lithium metal is a compelling choice as an anode material for high-energy-density batteries, attributed to its elevated theoretical specific energy and low redox potential. Nevertheless, challenges arise due to its susceptibility to high-volume changes and the tendency for dendritic development during cycling, leading to restricted cycle life and diminished Coulombic efficiency (CE). Here, we innovatively engineered a kind of porous biocarbon to serve as the framework for a lithium metal anode, which boasts a heightened specific surface area and uniformly dispersed ZnO active sites, directly derived from metasequoia cambium. The porous structure efficiently mitigates local current density and alleviates the volume expansion of lithium. Also, incorporating the ZnO lithiophilic site notably reduces the nucleation overpotential to a mere 16 mV, facilitating the deposition of lithium in a compact form. As a result, this innovative material ensures an impressive CE of 98.5% for lithium plating/stripping over 500 cycles, a remarkable cycle life exceeding 1200 h in a Li symmetrical cell, and more than 82% capacity retention ratio after an astonishing 690 cycles in full cells. In all, such a rationally designed Li composite anode effectively mitigates volume change, enhances lithophilicity, and reduces local current density, thereby inhibiting dendrite formation. The preparation of a high-performance lithium anode frame proves the feasibility of using biocarbon in a lithium anode frame.