Advancing polyimide electrodes from half-cells to pouch cells: Balancing $/kWh, stability, and scalability for practical Li-ion organic batteries

• Optimal PI composition (60 wt.%) balances capacity & rate capability in Li-ion half-cells. • High mass-loading PI electrodes (55 mg cm −2 ) achieve 8.5 mAh cm −2 , 129 mAh cm −3 . • Li_graphite//PI (99 mg cm −2 ) pouch cell deliver 210 Wh kg −1 , 32 mWh cm −2 . • 90 wt.% PI electrodes enable 185 Wh kg −1 , $70/kWh cost, and enhanced sustainability. • Rigorous benchmarking sets new standards for organic battery metrics and practical design. 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.