Synergizing Proton‐Dominated Storage and Electron Transfer for High‐Loading, Fast‐Rate Organic Anode in Metal‐Free Aqueous Zinc‐Ion Batteries

Abstract Developing suitable anode materials to fabricate metal‐free Zinc ion battery is a promising strategy to solve the issues of Zn metal anode, such as dendrite growth and side reactions. However, the reported anode materials face shortcomings such as unsatisfactory rate performance, low mass loading, etc. Herein, featuring synergetic proton‐dominated storage and electron transfer, a conjugated polyimide nanocomposite trapped by multi‐walled carbon nanotubes (PPN‐MWCNT) is developed for high‐loading, fast‐rate organic anode materials in metal‐free Zinc ion battery. Specifically, abundant hydrophilic active sites and nonplaner conjunctional structure in PPN achieve proton‐dominated storage with two steps four electrons mechanism, leading to fast ion diffusion, and the intimate contact between the polymer and MWCNT via in situ polymerization ensures the excellent charge transfer and robust structure. Thus, the PPN‐MWCNT electrode delivers low redox potential, ultrahigh rate performance (50 A g −1 ), superior loading capability (≈40 mg cm −2 ) and exceptional long‐term cyclability (over 12 000 cycles). More importantly, the full batteries assembled with PPN‐MWCNT anode and different cathodes deliver a high energy density of 106.4 Wh kg −1 (PPN‐MWCNT//MnO 2 ) and 83.7 Wh kg −1 (PPN‐MWCNT//active carbon‐I 2 ), exceeding the most reported metal‐free Zinc ion batteries.