Research On Modification Of Silicon-based Anode Material Coated With Different Silane Coupling Agents For Lithium-ion Batteries

To obtain the silicon-based anode materials with excellent cycling performance used in lithium-ion batteries, we treated the nano-silicon with silane coupling agent wishing that the silane layer can suppress the volumetric and structural change of silicon nanoparticles during the lithiation/delithiation process. In this paper, we firstly modified the particles with different silane coupling agents—KH560, WD-10 and A-171, and eventually, we got the silicon nanoparticles coated with silane layer. Secondly, we treated the particles with silane coupling agent(KH550) and poly-aniline to form a multi-component structure —PANI/KH550/Si. In addition, we tried to do sintering treatment with the silane coupling agent-coated nano-silicon.In this paper, we prepared the silane coupling agent-coated silicon nanoparticles by in-situ polymerization. The first reversible capacity of the KH560-coated material was 2057.3 m Ah/g, and it could still reach 1006.1 m Ah/g after 120 cycles, with higher capacity retention(48.9%). By adopting the silane coupling agent—WD-10, the first charge capacity of the nano-silicon was 2390.2 m Ah/g, which was 1785.5 m Ah/g after 30 charging and discharging cycles, with the coulombic efficiency of 95.3% and the capacity retention of 74.7%. The charge capacity for the first cyce of the A-171-coated nano-silicon was 2195.4 m Ah/g, and it was 1808.6 m Ah/g after 29 cycles. Besides, the coulombic efficiency of the A-171-coated material was 95.7%, and the capacity retention was 82.4% after 2 9 cycles. In general, the cycling performan of the silicon nanoparticles achieved great improvement. What’s more, we fabricated the multi-component structure material—PANI/KH550/Si. The reversible capacity of the particles with double layer was 2736.4 m Ah/g after 20 cycles at the current density of 100 m A/g and the capacity retention was 96.2%; Besides, the reversible capacity of the composite was 1052.5 m Ah/g after 60 cycles at the current density of 500 m A/g and the capacity retention was 74.2%.