Porous Cross-Linked Structured Conjugated Polymer Anode Materials for Lithium Storage Properties

Conjugated polymers possess fascinating properties such as abundant pore structure, large specific surface area, and tunable electronic structure that make them promising for electrochemical energy storage. Herein, the conjugated polymer PSFSO based on spirobifluorene and dibenzothiophene sulfone was synthesized for use as an anode material in lithium-ion batteries (LIBs). Benefiting from the unique porous cross-linked structure and the excellent stability of the polymer backbone, the PSFSO anode in the ester-based electrolyte was found to exhibit outstanding long-term cycle stability, delivering a high reversible specific capacity of 247.8 mAh g–1 after 1500 cycles at 500 mA g–1. Meanwhile, it also showed a high average capacity of 120.0 mAh g–1 at 1000 mA g–1, which was attributed to fast lithium-ion diffusion (7.17 × 10–12 S cm–1) and low charge transfer resistance (171.4 Ω). Compared with the ether-based electrolyte, PSFSO exhibited better structural stability and electrode retention when charged and discharged in the ester-based electrolyte. This work provided a feasible strategy for designing high-performance and low-cost organic lithium storage electrodes.