Achieving High‐Mass Loading Polyanionic Cathodes in Sodium‐Ion Batteries Through Accessible Laboratory‐Scale Dry‐Processing Strategies

ABSTRACT Sodium‐ion batteries require high‐mass‐loading electrodes to achieve competitive cell‐level energy density for large‐scale energy storage. However, conventional wet processing often induces structural heterogeneity and mechanical instability in thick electrodes. In this work, we demonstrate a versatile and accessible laboratory‐scale dry‐processing strategy requiring conventional ball‐milling and thermal pressing. The degree of PTFE fibrillation can be regulated through controlled ball‐milling to construct a stable and continuous electrode architecture. The optimized dry‐processed sodium vanadium manganese phosphate (NVMP) cathode, with active material loading exceeding 40 mg cm −2 , exhibits reduced polarization, stable interface evolution, and boosted ion diffusion, which meets the requirements of lab‐scale testing and research for thick electrodes with high capacity. Hard‐carbon||NVMP full cells further demonstrate reliable rate capability and prolonged cycling stability. This work demonstrates a versatile and accessible laboratory‐scale strategy to construct stable thick‐electrode architectures by regulating PTFE fibrillation. The methodology provides a convenient route for laboratory research on dry‐processed electrodes and high‐capacity sodium‐ion batteries.