A Lignin-Based Carbon Anode with Long-Cycle Stability for Li-Ion Batteries

Due to its wide source and low cost, biomass-based hard carbon is considered a valuable anode for lithium-ion batteries (LIBs). Lignins, as the second most abundant source in nature, are being intensively studied as candidate anode materials for next generation LIBs. However, direct carbonization of pure lignin usually leads to low specific surface area and porosity. In this paper, we design a porous carbon material from natural lignin assisted by sacrificing a metal-organic framework (MOF) as the template. The MOF nanoparticles can disperse the lignin particles uniformly and form abundant mesopores in the composites to offer fast transfer channels for Li⁺. The as-prepared carbon anode shows a high specific capacity of 420 mAh g^-1 with the capacity retention of 99% after 300 cycles at 0.2 A g^-1. Additionally, it keeps the capacity retention of 85% after long cycle of 1000 cycles, indicating the good application value of the designed anode in LIBs. The work provides a renewable and low-cost candidate anode and a feasible design strategy of the anode materials for LIBs.