Wood outlasts graphite: revolutionary birch biomass-based carbon anodes for long-life lithium-ion batteries

Here, we present carbon anode materials derived from birch biomass (BCAM) with hierarchical micro-mesoporous structure, largely amorphous carbon framework and abundant active sites for lithium storage and efficient ion-transport - prepared through phosphoric acid activation followed by high-temperature pyrolysis at 1000 °C. BCAM materials deliver a reversible capacity of 915 mA h g^-1 at 1C after 1000 cycles, maintain 412 mA h g^-1 after 2000 cycles at 2.5C, and retain 235 mA h g^-1 after 5000 cycles at 5C with ca. 100% coulombic efficiency. As for comparison, a cell made with commercial graphite as also tested, the results showed a reversible capacity of 365 mA h g^-1 at 1C after 400 cycles, a much lower capacity than that of BCAM anode material. Kinetic analysis indicates a substantial pseudocapacitive contribution, particularly at higher scan rates, which supports fast charge-discharge behavior. In addition, electrochemical impedance spectroscopy reveals low charge-transfer resistance and favorable lithium-ion diffusion kinetics. In total, these birch-derived carbons provide a steppingstone in robust, low-cost, and environmentally benign anode materials, and offer a promising route towards long-life time and sustainable lithium-ion batteries (LIBs).