The solvation structure of Li+ in chemical prelithiation reagent plays a key role in improving the low initial Coulombic efficiency (ICE) and poor cycle performance of silicon-based materials. Nevertheless, the chemical prelithiation agent is difficult to dope active Li+ in silicon-based anodes because of their low working voltage and sluggish Li+ diffusion rate. By selecting the lithium–arene complex reagent with 4-methylbiphenyl as an anion ligand and 2-methyltetrahydrofuran as a solvent, the as-prepared micro-sized SiO/C anode can achieve an ICE of nearly 100%. Interestingly, the best prelithium efficiency does not correspond to the lowest redox half-potential (E1/2), and the prelithiation efficiency is determined by the specific influencing factors (E1/2, Li+ concentration, desolvation energy, and ion diffusion path). In addition, molecular dynamics simulations demonstrate that the ideal prelithiation efficiency can be achieved by choosing appropriate anion ligand and solvent to regulate the solvation structure of Li+. Furthermore, the positive effect of prelithiation on cycle performance has been verified by using an in-situ electrochemical dilatometry and solid electrolyte interphase film characterizations.

Non-negligible volume change is a troublesome problem for the commercial application of silicon oxide (SiO x ). It is acknowledged that polymer binders' design is a promising method to promote the commercialization of SiO x . Herein, we proposed a three-dimensional (3D) dynamic cross-linked binder (CS-EDTA) via the ionic bonding between chitosan (CS) and ethylenediaminetetraacetic acid (EDTA). With excellent adhesive strength, CS-EDTA could tighten the connection of electrode constituents and prevent electrode delamination. Due to the reversible ionic bond, the 3D dynamic cross-linked structure of CS-EDTA could be repaired at ruptured points, which is favorable for alleviating the volume expansion of SiO x , resulting in enhanced structural stability of SiO x . Based on CS-EDTA, SiO x @ CS-EDTA exhibits improved cycling stability and electrochemical kinetics compared with SiO

Polymer binders play an important role in enhancing the electrochemical performance of silicon-based anodes to alleviate the volume expansion for lithium-ion batteries. It is difficult for common one-dimensional (1D) linear binders to limit the volume expansion of a silicon-based electrode when combined with silicon-based particles with scant binding points. Therefore, it is necessary to design a three-dimensional (3D) network structure, which has multiple binding points with the silicon particles to dissipate the mechanical stress in the continuous charge and discharge circulation. Here, a covalent and hydrogen bond synergist 3D network green binder (poly(acrylic acid) (PAA)−dextrin 9 (Dex 9 )) was prepared by the simple in situ thermal condensation of a onedimensional liner binder PAA and Dex in the electrode fabrication process. The optimized SiO x @PAA-Dex 9 electrode exhibits an initial Coulombic efficiency (ICE) of 82.4% at a current density of 0.2 A g −1 . At a high current density of 1 A g −1 , it retains a capacity of 607 mAh g −1 after 300 cycles, which is approximately twice as high as that of the SiO x @PAA electrode. Furthermore, the results of in situ electrochemical dilatometry (ECD) and characterization of electrode structures demonstrate that the PAA-Dex 9 binder can effectively buffer the huge volume change and maintain the integrity of the SiO x electrodes. The research overcomes the low electrochemical stability difficulty of the 3D binder and sheds light on developing the simple fabrication procedure of an electrode.