Selectively accelerated lithium ion transport to silicon anodes via an organogel binder

•An organogel binder was designed for silicon anodes used in lithium ion batteries.•It consisted of Li+ transport units and physical integration units.•Selectively accelerated Li+ transport to (out of) Si improved its overall kinetics.•Strong adhesion and suitable mechanical properties supported durable cyclability.

Silicon, a promising high-capacity anode material of lithium ion batteries, suffers from its volume expansion leading to pulverization and low conductivities, showing capacity decay during cycling and low capacities at fast charging and discharging. In addition to popular active-material-modifying strategies, building lithium-ion-rich environments around silicon surface is helpful in enhancing unsatisfactory performances of silicon anodes. In this work, we accelerated lithium ion transport to silicon surface by using an organogel binder to utilize the electroactivity of silicon in a more efficient way. The cyanoethyl polymer (PVA-CN), characterized by high lithium ion transference number as well as appropriate elastic modulus with strong adhesion, enhanced cycle stability of silicon anodes with high coulombic efficiency even at high temperature (60 °C) as well as at fast charging/discharging rates.

Graphical abstractSelectively accelerated Li+ transport through an organogel binder secured improved kinetics of silicon lithiation while its strong cohesion/adhesion and optimized mechanical properties supported durable cyclability of silicon-based lithium ion batteries.Figure optionsDownload full-size imageDownload as PowerPoint slide