Performance Enhancement of Silicon Alloy-Based Anodes\nUsing Thermally Treated Poly(amide imide) as a Polymer Binder for\nHigh Performance Lithium-Ion Batteries

Abstract

The\ndevelopment of silicon-based anodes with high capacity and good cycling\nstability for next-generation lithium-ion batteries is a very challenging\ntask due to the large volume changes in the electrodes during repeated\ncycling, which results in capacity fading. In this work, we synthesized\nsilicon alloy as an active anode material, which was composed of silicon\nnanoparticles embedded in Cu–Al–Fe matrix phases. Poly­(amide\nimide)­s, (PAI)­s, with different thermal treatments were used as polymer\nbinders in the silicon alloy-based electrodes. A systematic study\ndemonstrated that the thermal treatment of the silicon alloy electrodes\nat high temperature made the electrodes mechanically strong and remarkably\nenhanced the cycling stability compared to electrodes without thermal\ntreatment. The silicon alloy electrode thermally treated at 400 °C\ninitially delivered a discharge capacity of 1084 mAh g^–1 with good capacity retention and high Coulombic efficiency. This\nsuperior cycling performance was attributed to the strong adhesion\nof the PAI binder resulting from enhanced secondary interactions,\nwhich maintained good electrical contacts between the active materials,\nelectronic conductors, and current collector during cycling. These\nfindings are supported by results from X-ray photoelectron spectroscopy,\nscanning electron microscopy, and a surface and interfacial cutting\nanalysis system.