Fabrication of High-Performance Organic Electrodes through Field-Induced Charge Transfer for Li-Ion Batteries

Despite promising theoretical predictions, the practical performance of organic-based electrodes often falls short of expectations due to a low density of active sites, limited ion diffusivity, and high solubility in the electrolyte. In this study, we present an organic nanocomposite cathode with exceptional electrochemical stability achieved through an electric field-induced charge-transfer reaction in the nanocomposite, comprising 5,10-dihydro-5,10-dimethylphenazine (DMPZ) and perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA). Cryogenic milling was adopted to form a porous nanocomposite structure. The charge-transfer reaction effectively suppresses elution, and the porous structure increases the density of active sites. As a result, the porous nanocomposite showed a remarkable improvement in organic cathode performance, including an unprecedented high capacity retention of 90% over 600 cycles, a high initial capacity of 209 mAh g-1, and excellent reversibility at high current densities. The performance enhancement mechanism of the organic nanocomposite cathode is elucidated through experimental analyses, including ex-situ XPS, PiFM, FTIR, and DFT calculations on the energy levels of organic components.