Precisely Prelithiated Polyacrylic Acid Binder Improving Electrochemical Performance of Micron-Sized Silicon Anodes for Lithium-Ion Batteries

Graphical Precisely prelithiation not only enhances the mechanical properties of PAA binders but also provides extra Li for electrode to form a stable SEI layer, thus improving electrochemical performance of micron-sized silicon anodes for lithium-ion batteries. Among those prelithiated PAAs (LiPAAs), LiPAA-3 exhibits the best adhesion and strength, leading to a remarkable reversible capacity and an excellent ICE of Si−LiPAA-3 electrode. Silicon, serving as an anode material of Li-ion batteries, offers a theoretical capacity significantly higher than graphite, but its practical application is hindered by poor conductivity, low lithium ion diffusivity, and severe volumetric expansion. Here, a simple and eco-friendly methodology is proposed to synthesize precisely prelithiated polyacrylic acid binder, optimizing the interface between the binder and micron Si particles. The incorporation of these binders not only mitigates the detrimental effects of volumetric expansion but also enhances mechanical strength, and ionic conductivity of the anode, significantly improving the initial Coulombic efficiency (ICE), cycling stability, and rate performance of micron-sized Si anodes. This study not only highlights the potential of prelithiated binders in overcoming the limitations of micron-sized Si anodes but also sets a new benchmark for the development of high-capacity, eco-friendly Li-ion batteries.