Cross-Linked Binary Polymeric Binder of Polyacrylic Acid-Carboxymethyl Cellulose for Improving Phosphorus Anode

Phosphorus (P) is a promising anode material with high capacity (2596 mAh g-1 and 6075-6924 mAh cm-3), low lithium-ion diffusion barrier (0.08 eV), and appropriate lithiation potential (approximate to 0.7 V vs Li+/Li). However, the problems of huge volume expansion (approximate to 300%), low electronic conductivity (10-14-102 S cm-1), and soluble intermediates (lithium polyphosphides, LixpPs) restrict its performance. In this work, a robust, cross-linked binary polymeric binder polyacrylic acid-carboxymethyl cellulose (PAA/CMC) binder is designed, which has good Li+ conductivity and is not reactive with lithium polyphpsphode (LixpPs). The resulting composite P/CNT-PAA/CMC displays a high reversible capacity of 1230.2 mAh g-1 after 200 cycles at 1300 mA g-1, achieving 10 times as much as the control sample P/CNT-PVDF. The volume expansion after lithiation of P/CNT-PAA/CMC is only 6%, far less than that of the control sample (83%). Phosphorus is a promising anode material with high capacity, low lithium-ion diffusion barrier, and appropriate lithiation potential. However, the problems of huge volume expansion and soluble intermediates restrict its performance. A robust, cross-linked binary polymeric PAA/CMC is designed, which has good Li+ conductivity and is not reactive with LixpPs. The volume expansion after lithiation of P/CNT-PAA/CMC is only 6%.image