Poria cocos waste-derived cellulose-based biochar as an advanced porous anode material for lithium-ion batteries

The biochar converted from waste materials has shown excellent performance as an anode material for lithium-ion batteries (LIBs), and is considered to be one of the effective strategies to solve environmental pollution and energy shortage. However, due to the diverse intrinsic structure and complex internal compositions of waste materials, the selection and design of waste materials still face a significant challenge. Herein, using cellulose-rich Poria cocos waste as the raw material, a porous biochar anode material was prepared for the first time by a chemical-thermal combined treatment method. The biochar exhibits an abundant porous structure with a high specific surface area of 2290.6 m² g⁻¹, according to the results of physical characterization. Furthermore, the biochar as an anode material of LIBs delivers an impressive initial reversible specific capacity of 1139.64 mAh g⁻¹ at 100 mA g⁻¹, outstanding rate capability, and amazing cycling stability with a capacity of 806.63 mAh g⁻¹ after 300 cycles. Even at 1000 mA g⁻¹, the biochar still exhibits excellent cycling stability with a capability of 227.85 mAh g⁻¹ after 300 cycles. Particularly, the biochar anode can still exhibit an excellent electrochemical performance even at 60 °C. Therefore, the biochar based on Poria cocos waste provides a sustainable, low-cost route for producing advanced high-capacity anode materials for LIBs.