Prefabrication of Trinity Functional Binary Layers on a Silicon Surface to Develop High-Performance Lithium-Ion Batteries

The silicon (Si) anode is widely recognized as the most prospective next-generation anode. To promote the application of Si electrodes, it is imperative to address persistent interface side reactions caused by the huge volume expansion of Si particles. Herein, we introduce beneficial groups of the optimized binder and electrolyte on the Si surface by a codissolution method, realizing a trinity functional layer composed of azodicarbonamide and 4-nitrobenzenesulfonyl fluoride (AN). The trinity functional AN interfacial layer induces beneficial reductive decomposition reactions of the electrolyte and forms a hybrid solid-electrolyte interphase (SEI) skin layer with uniformly distributed organic/inorganic components, which can enhance the mechanical strength of the overall electrode, restrain harmful electrolyte depletion reactions, and maintain efficient ion/electron transport. Hence, the optimized Si@AN11 electrode retains 1407.9 mAh g(-1) after 500 cycles and still delivers 1773.5 mAh g(-1) at 10 C. In stark contrast, Si anodes have almost no reserved capacity at the same test conditions. Besides, the LiNi0.5Co0.2Mn0.3O2//Si@AN11 full-cell maintains 141.2 mAh g(-1) after 350 cycles. This work demonstrates the potential of developing multiple composite artificial layers to modulate the SEI properties of various next-generation electrodes.

Automated summary

To address the interface side reactions caused by volume expansion of Si particles, beneficial groups of binder and electrolyte were introduced on Si surface, forming a trinity functional layer. This layer enhances mechanical strength, restrains harmful reactions, and maintains efficient ion/electron transport, improving the overall performance of the Si electrode.