Organic batteries using abundant and recyclable organic electrode materials provide a sustainable and environmentally friendly alternative to commercial lithium-ion batteries1–5, which rely on resource-limited mineral-derived inorganic electrode materials6–8. However, the practical use of organic batteries has been severely hindered by the intrinsic insulation and dissolution of organic electrode materials9,10. Here we report practical organic batteries using an n-type conducting polymer cathode, poly(benzodifurandione) (PBFDO), which exhibits excellent mixed ionic and electronic transport and low solubility. The PBFDO cathode maintains its n-doped state throughout the electrochemical processes and exhibits stable and reversible redox characteristics, high electrical conductivities and significant lithium-ion diffusion coefficients, without the need for additional conductive additives. Consequently, ultrahigh-mass-loading polymer cathodes, with mass loadings up to 206 mg cm−2, are realized, delivering a high areal capacity of 42 mAh cm−2 and demonstrating robust cycling stability. Furthermore, practical 2.5 Ah lithium–organic pouch cells were fabricated, achieving an impressive energy density of 255 Wh kg−1. Notably, the conducting polymer cathode operates efficiently over a wide temperature range from −70 °C to 80 °C and demonstrates excellent flexibility and safety, marking considerable potential for applications in extreme conditions and wearable electronics.
