Advancing Polyimide Electrodes From Half-Cells to Pouch Cells: Balancing $/kWh, Stability, and Scalability for Practical Li-ion Organic Batteries

Organic batteries hold great promise for sustainable energy storage, yet research has largely focused on material-level development, with practical optimization remaining underexplored. This work systematically addresses this gap by optimizing polyimide (PI) composition, mass loading, and electrode design, starting with Li-ion half-cells. Even at high mass loadings (up to 55 mg cm⁻²), PI electrodes exhibited exceptional gravimetric, areal, and volumetric capacities (155 mAh g⁻¹, 8.5 mAh cm⁻², 129 mAh cm⁻³) and outstanding specific energies (416 Wh kg⁻¹, 22.9 mWh cm⁻², 371 Wh L⁻¹), among the highest reported for organic Li-ion electrodes. Moving to practical systems, semi-organic Li-ion full cells, such as Li_graphite//PI, Li_LTO//PI, PI//LFP, and PI//NMC, assembled in both coin- and pouch-type configurations demonstrate PI electrode's viability, with Li_graphite//PI pouch cells achieving 210 Wh kg⁻¹ and 32 mWh cm⁻² at 2.2 V, alongside robust cycling stability. Finally, increasing PI content to 90 wt.% at 50 mg cm⁻² further enhances gravimetric energy density (185 Wh kg_electrodes⁻¹), reduces cost ($70 per kWh), and improves sustainability without compromising performance. These findings highlight PI's potential for next-generation organic batteries and provide a rigorous performance benchmark, setting new standards for evaluating and commercializing organic electrode materials.