Dendrimer Based Binders Enable Stable Operation of Silicon Microparticle Anodes in Lithium-Ion Batteries

High-capacity anode materials (e.g., Si) are highly needed for high energy density battery systems, but they usually suffer from low initial coulombic efficiency (CE), short cycle life, and low-rate capability caused by large volume changes during the charge and discharge process. Here, a novel dendrimer-based binder for boosting the electrochemical performance of Si anodes is developed. The polyamidoamine (PMM) dendrimer not only can be used as binder, but also can be utilized as a crosslinker to construct 3D polyacrylic acid (PAA)-PMM composite binder for high-performance Si microparticles anodes. Benefiting from maximum interface interaction, strong average peeling force, and high elastic recovery rate of PAA-PMM composite, the Si electrode based on PAA-PMM achieves a high specific capacity of 3590 mAh g(-1) with an initial CE of 91.12%, long-term cycle stability with 69.80% retention over 200 cycles, and outstanding rate capability (1534.8 mAh g(-1) at 3000 mA g(-1)). This work opens a new avenue to use dendrimer chemistry for the development of high-performance binders for high-capacity anode materials.

Automated summary

A novel dendrimer-based binder is developed to improve the electrochemical performance of Si anodes. The composite binder, consisting of PMM dendrimer and PAA crosslinker, allows for maximum interface interaction, strong average peeling force, and high elastic recovery rate. The Si electrode based on this binder exhibits high specific capacity, long-term cycle stability, and outstanding rate capability.