上海科技大学知识管理系统

Redox-active ionic polymers show low solubility in organic electrolytes and high ionic/electronic conductivity, but most of them coupling with non-active counter ions present low specific capacity. Herein, we design polyviologens with halides (Br- or I-) as counter anions, which are also redox-active and can participate in energy storage. Poly(viologen halide) electrodes exhibit high initial specific capacity (192 mA h g(-1)) and high discharge voltage (similar to 3.7 V). When using carbon cloth as a current collector, the cathode with high mass loading (80 wt%) of poly(viologen iodide) presents high capacity, improved cycling stability (89% capacity retention after 600 cycles at 0.1 A g(-1)) and rate performance (110 mA h g(-1) at 2 A g(-1)). In addition, the charge storage mechanism is investigated by in situ Raman and ex situ X-ray photoelectron spectroscopy.