Quasi-dry processing of graphite anodes with hybrid binder system for high mass-loading lithium-ion batteries

Dry electrode processing is a promising approach for fabricating thick, high mass-loading electrodes without the limitations of solvent-based slurry methods. However, its application to graphite anodes is hindered by the electrochemical instability of polytetrafluoroethylene (PTFE), the standard dry-process binder. Here, we introduce a quasi-dry processing anodes with hybrid binder strategy that partially substitutes PTFE with carboxymethyl cellulose (CMC) as a multifunctional binder. Ethanol facilitates uniform mixing of CMC with the dry mixture, enabling effective integration without high-temperature drying. We investigated various CMC substitution levels to determine the optimal PTFE-to-CMC ratio. The resulting quasi-dry processing of graphite electrode with hybrid binder (HGE-1) with 1 wt% CMC demonstrates improved initial Coulombic efficiency, rate capability, and cycling stability compared to PTFE-only graphite electrodes. These enhancements stem from the CMC co-binder, which enhances Li⁺ transport, improves adhesion, maintains electrode integrity, and reduces direct contact between PTFE and graphite domains. This study presents a cost-effective co-binder strategy using commercially available materials to advance PTFE-based dry processing for lithium-ion battery anodes.