Lignin-Based Polymer Networks Enabled N, S Co-Doped Defect-Rich Hierarchically Porous Carbon Anode for Long-Cycle Li-Ion Batteries
Wen Luo, Qi He, Chaoqun Zhang, Zhenyu Jiang, Yi Cheng, Haisong Wang
Abstract
The commercial graphitic anode with low specific capacity and serious lithium dendrite growth has limited further improvements of Li-ion batteries (LIBs). Here, we report a hierarchical porous hard carbon with N, S codoping (LSCF) that is synthesized using trifunctional sodium lignosulfonate (LS) from the pulp waste as the self-sacrificing template, carbon source, sulfur source, and natural chitosan as both the carbon source and nitrogen source. The strong hydrogen-bond interaction between the LS and chitosan enabled the robust stability of the carbon framework. And the self-template of sulfates and carbonates from LS enabled the formation of the hierarchical porous structure. First-principles calculations indicate that the hierarchical porous LSCF carbon with heteroatom doping has a lower diffusion barrier of Li + and a higher electron conductivity. As an anode for LIBs, the LSCF delivers the specific capacity of 350 mAh g –1 at 100 mA g –1 with 85% retention after 1000 cycles. This work offers a one-step and low-cost method to fabricate the porous hard carbon anode for LIBs with dual-atom doping based on green natural polymers.