A synergistic mechanism: In-situ constructed Ag/Cu bimetallic sandwich structure organic electrode for dual-ion batteries

Organic polymer materials are promising for energy storage owing to their high safety and structural tunability. However, their practical application is hindered by poor cycling stability, low electrical conductivity, and high solubility. This study utilized the silver nitrate (AgNO 3 ) displacement reaction to innovatively in situ construct a sandwich-structured organic electrode with nanomesh metal-based SEI film. It effectively addressed the limitations of the two interface layers of active material/electrolyte and active material/collector to achieve interfacial stabilization and fast ion transport. The three-dimensional mesh metal-based artificial SEI layer with attached nanoparticles not only effectively inhibits the electrode material from being attacked by the electrolyte and reduces the solubility of organic materials, but also the attached nanoparticles can enhance the conductivity of the material. In addition, the pure Ag metal layer between the active material and the Cu foil collector can effectively improve the electrical conductivity and accelerate the electron transfer, which plays a key role in keeping the internal resistance stability of the battery. The composite electrode material exhibits excellent rate performance and stable long cycling performance at a high rate (46.1 mAh g −1 after 2000 cycles at 20 C, 1 C = 223 mAh g −1 ). Furthermore, Density functional theory (DFT) calculations and theoretical analysis provided detailed explanations of the energy storage pathways and utilized the electronic structure to reveal the synergistic effect mechanism existing among the sandwich structures. Therefore, providing a new strategy for designing organic polymer materials to be used in high-performance energy storage devices in the future.