Enhancing Fast‐Charging Capability of NMC811 Cathodes for Lithium‐Ion Batteries via Cathode Composition and Mechanical Pressure Optimisation

The fast‐charging performance of lithium‐ion batteries remains a critical barrier to widespread electric vehicle adoption. This study systematically investigates the effects of cathode composition, cathode thickness, and cell internal mechanical pressure on the fast‐charging capability of NMC811 (LiNi 0.8 Mn 0.1 Co 0.1 O 2 )‐based coin half‐cells. Different cathode compositions with varying ratios of active material, conductive carbon (Timcal C65), and polyvinylidene fluoride binder were evaluated at two loading levels under both non‐pressurised and pressurised conditions. Rate capability tests (0.1–2C) and long‐term cycling (200 cycles at 2C charge/C/3 discharge) were performed alongside electrochemical impedance spectroscopy. Results demonstrated that the 85/05/10 compositions (active material/carbon black/binder, wt%) exhibited superior performance, delivering higher specific capacity at 2C charging and better long‐term stability compared to other tested compositions. Application of internal mechanical pressure significantly reduced charge transfer resistance and Warburg impedance, particularly benefiting compositions with lower binder content. Thinner electrodes showed improved high‐rate performance and cycling stability, though at the expense of areal capacity. This work highlights that increasing conductive agent and binder fractions beyond conventional formulations (>90 wt% active material) enhanced fast‐charging capability while maintaining mechanical integrity, offering new design strategies for next‐generation battery electrodes. Optimised NMC811 cathodes with increased binder and conductive carbon fractions (85/05/10 wt%) and applied internal pressure exhibit superior fast‐charging performance and cycling stability. This study highlights how composition and mechanical pressure synergistically enhance charge transport in Ni‐rich lithium‐ion batteries.