Research On Modifition Of Silicon Anode Material For Lithium-ion Batteries

Based on the nano silicon surface modification, this paper has improved theircycling stability and efficiency, thereby improving their electrochemical properties.Firstly, the chemical modification of nano-silicon copper has been studied, as wellas the preparation of high conductivity of doped polyaniline conductive state, andthe preparation of in-situ polymerization of polyaniline on modified nano-siliconalloy coated anode materials; Another major of the paper is the use of silanecoupling agent KH570and KH550to the nano-modified silicon and polyanilinewas prepared by in-situ polymerization of silane coupling agent modified coatednano silicon anode materials; In addition, the in-situ polymerization ofpolyaniline-coated carboxyl-modified nano-silicon anode materials were alsoprepared.By the study of doped polyaniline synthesis conditions studied, the highconductivity doped polyaniline was prepared, with a conductivity of26.0S/cm.Herein, the modification of the electroless copper plating efficiency by ultrasonicnanometer silicon-silicon negative electrode material obtained the initial coulombicefficiency of74.8%, the first reversible capacity of1607.1mAh/g, the capacityretention after50cycles of64.9%and the reversible capacity of1042.9mAh/g.Compared with pure nanocrystalline silicon particles, the cycling stability havebeen greatly improved. By polyaniline prepared in situ polymerization modifiednano-silicon alloy coated anode material, its initial coulombic efficiency was71.2%, while the first reversible capacity was1115.0mAh/g, and the capacityretention after40cycles was80.8%, reversible capacity901.3mAh/g. Through thesilane coupling agent KH570modified the nano silicon, the best results were asfollows: initial coulombic efficiency of62.7%; initial reversible capacity1845.1mAh/g; the capacity retention after20cycles was115.4%; the reversiblecapacity of2129.9mAh/g. Prepared by in situ polymerization of polyaniline coatedwith a silane coupling agent KH570modified nano-silicon anode material, itsinitial efficiency of65.1%, the first reversible capacity1631.7mAh/g, the capacityretention after10cycles was99.8%, a reversible capacity of1627.9mAh/g.Relative to pure nanocrystalline silicon, the performance has been greatlyimproved. In addition, this paper also carried out the nano-silicon modification ofsilane coupling agent KH550and the exploration of carboxyl silicon as anodematerials.