Cross-linked binary polymeric binder of β-cyclodextrin-carboxymethyl cellulose for black phosphorus anode in lithium-ion batteries

In the field of lithium-ion battery (LIB) research, black phosphorus (BP) emerges as a promising anode material due to its high electrical conductivity and capacity. However, its significant volume expansion during cycling can lead to electrode pulverization and rapid capacity fade. In this study, a novel network binary polymer binder composed of carboxymethyl cellulose (CMC) and β-cyclodextrin (β-CD) is developed. Intermolecular forces crosslink CMC and β-CD, while strong intermolecular forces connect CMC and β-CD to BP. Graphite (G) is bonded to BP through P–C and P–O–C linkages, forming a composite anode. Research indicates that this intricate network structure effectively accommodates the volume changes of black phosphorus during charging and discharging, preserving the electrode structural integrity and enabling high reversible capacity. The CMC-β-CD electrode exhibits excellent cycle stability, maintaining a capacity retention rate of 70.3% after 300 cycles at 2 A g −1 , which is significantly higher than the electrodes using CMC (40.8%) and PVDF (40.6%) binders.