Hybrid 0D-2D conductive networks enable low-tortuosity transport in solvent-free thick NCM811 cathodes

The rapid expansion of electric vehicles (EVs) and large-scale energy storage systems (ESS) demands scalable manufacturing strategies for high-energy-density lithium-ion batteries. Solvent-free dry electrode processing enables thick electrodes but inevitably increases transport resistance and Li + pathway tortuosity, leading to polarization and performance degradation. Herein, we investigate the role of conductive additive dimensionality in governing ion transport behavior in ∼150 μm-thick Ni-rich NCM811 cathodes fabricated via a dry process. By systematically controlling the ratio of zero-dimensional (0D) Super P and two-dimensional (2D) graphene nanoplatelets (GNPs), we isolate geometric effects on Li + transport under comparable porosity and structural conditions. Effective ionic tortuosity was quantified using symmetric cell impedance analysis. The S75G25 electrode exhibited the lowest tortuosity (τ = 6.09), indicating improved pathway continuity. Although all electrodes showed similar redox behavior and low-rate capacity, pronounced differences emerged under transport-limited conditions. The S75G25 composition delivered 194 mAh g −1 at 0.2 C and 125 mAh g −1 at 0.5 C, while higher-tortuosity electrodes exhibited accelerated capacity fading and structural degradation, including particle cracking and secondary particle collapse. These results establish effective tortuosity as a key structural descriptor linking pore architecture, transport uniformity, and degradation in dry-processed thick Ni-rich cathodes, providing guidance for scalable high-loading electrode design.