Encapsulating silicon into conjugated N-doped carbon with multifunctional citric acid binder for lithium-ion battery

Silicon has become a promising anode material for lithium-ion batteries (LIBs) owing to its high theoretical capacity and low electrochemical potential (vs. Li/Li+). However, its practical application is still hindered by structure degradation and comparable poor capacity retention. Herein, a novel hybrid modification method was proposed to effectively alleviate silicon volume stress. In this structure, polyvinylpyrrolidone (PVP) was served as inner carbon sources to disperse silicon nanoparticles and achieved conjugated N-doped carbon shell coating. Micro-molecule citric acid served as inert layer was to chosen as binder to crosslink silicon particles as well as adjust the component of solid electrolyte interface (SEI) to further stabilize cycling properties. As a result, the obtained electrode has reached to high reversible specific capacity of 1015 mAh/g over 600 cycles at 500 mA/g. This simple combination preparation process would open a new route to exploit silicon electrode.