Polymer Chainmail: Steric Hindrance and Charge Compensation of Anion‐Doped PEDOT to Boost Stress Deformation of Compressible Supercapacitor

Conducting polymers with high theoretical capacitance and deformability are among the optimal candidates for compressible supercapacitor electrode materials. However, achieving both mechanical and electrochemical stabilities in a single electrode remains a great challenge. To address this issue, the “Polymer Chainmail” is proposed with reversible deformation capability and enhances stability because of the steric hindrance and charge compensation effect of doped anions. As a proof of concept, four common anions are selected as dopants for Poly(3,4‐ethylenedioxythiophene) (PEDOT), and their effects on the adsorption and diffusion of H+ on PEDOT are verified using density functional theory calculations. Owing to the film formation effect, the PF6- ${{\rm{PF}}_6^- }$ doped PEDOT/nitrogen‐doped carbon foam exhibits good mechanical properties. Furthermore, the composite demonstrates excellent rate performance and stability due to suitable anion doping. This finding provides new insights into the preparation of electrochemically stable conductive polymer‐based compressible electrode materials. After the poly(3,4‐ethylenedioxythiophene) (PEDOT) films known as “Polymer Chainmail” were modified by PF−6 anion doping, the ion adsorption and diffusion processes on the PEDOT chains were significantly optimized due to the steric hindrance and charge compensation effects, so the cycling stability (retaining 95.9 % after 20,000 cycles) and rate performance (retaining 81.1 % at 20 mA cm−3) were improved.