Multi layered porous nitrogen-rich biochar materials derived from soybean cellulose for lithium metal anode three-dimensional skeleton in lithium batteries

Lithium metal, renowned for its ultra-high theoretical specific capacity and low electrochemical potential, is a promising anode material for high-energy-density batteries. However, its commercialization is impeded by issues such as uncontrolled Li dendrite growth and volumetric expansion during cycling. Herein, we report the synthesis of a nitrogen- and Si₃N₄-enriched porous based biochar derived from antibiotic mycelial residues rich in soybean cellulose, which serves as a three-dimensional skeleton for Li metal anodes. This biochar, characterized by a high specific surface area and a porous structure, along with its excellent electrical conductivity, facilitates uniform Li nucleation and growth, thereby mitigating dendrite formation. Results show that the biochar electrode after lithium deposition can achieve stable cycling for over 1200 h at a capacity of 2 mAh cm^-2. When integrated with a NCM cathode in a coin cell configuration, the coin-type full cell demonstrates a capacity retention of 85.7 % after 300 cycles at a 0.3C rate. Additionally, pouch cell tests exhibit superior cycling stability with high-capacity retention. This study not only presents an innovative approach to the management of harmful biological waste high in soybean cellulose but also contributes to the advancement of Li metal anode materials for next-generation batteries.