Self-healing silicon-sodium alginate-polyaniline composites originated from the enhancement hydrogen bonding for lithium-ion battery: A combined simulation and experiment study

Silicon anode suffers from poor intrinsic conductivity and dramatic volume change during discharge/charge process, which hinders its commercialization for high energy density lithium-ion batteries. To address these challenges, silicon-sodium alginate-polyaniline composites are rationally designed and synthesized via in-situ polymerization. A hydrogen bond self-healing process occurs during lithiation and delithiation to accommodate the strong volumetric modification, so that the composites perform excellent electrochemical performance, with a capacity of 1099.5 mAh.g(-1) after 200 cycles at the current density of 1.0 A.g(-1). In view of the density functional theory calculations, the synergy effect of sodium alginate and polyaniline enhances the hydrogen bonding of the silicon and polymers, increases the electron transport capability, and results in excellent electrical, mechanical integrity and conductivity of the electrodes. Our work not only provides a facile procedure to prepare unique conducting three dimensional network structured composites as a commercial anode but also reveals the mechanism that the silicon nanoparticles avoids electrode pulverization via hydrogen bonding self-healing process.