Preparation and process optimization of porous silicon anode materials for lithium-ion battery
In order to improve the performance of silicon-based anode materials and reduce the preparation cost,porous sili-con anode materials were prepared by metal-assisted chemical etching method using micron-grade silicon as raw material.The method showed the advantages of simple and controllable steps,low cost and easy large-scale generation.By means of field emission scanning electron microscopy and battery testing system,the morphology and properties of silicon anode ma-terials prepared under different process parameters were compared and analyzed,so as to optimize the process.The results showed that the optimum technological parameters were as follows:AgNO3 concentration was about 0.015 mol/L,reaction time of Galvani was 1～4 min,the CHF/(CH2O2+CHF)in etching agent was 70%～90%.The electrochemical performance of po-rous silicon anode material prepared under suitable process parameters was obviously superior to that of silicon anode mate-rial.After 50 cycles at 0.5C,the capacity of porous silicon anode material was still 1 130.7 mA·h/g.Under 2C and 5C rate tests,there were still high specific capacities of 929 and 669 mA·h/g,respectively.The results showed that porous silicon anode materials could effectively alleviate the bulk expansion and poor conductivity of the monomeric silicon anode materi-als,thus effectively improving its electrochemical properties.
lithium-ion batteryanode materialporous siliconmetal-assisted chemical etching
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