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

Abstract 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 (≈0.7 V vs Li⁺/Li). However, the problems of huge volume expansion (≈300%), low electronic conductivity (10⁻¹⁴–10² S cm⁻¹), and soluble intermediates (lithium polyphosphides, Li_xpPs) 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 (Li_xpPs). 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%).