Preparation Of Silicon-Based Anode Alloy For Lithium Ion Batteries By Molten Salt Electrolysis

Silicon-based materials as an electrode material most likely to replace carbon-based materials in the future to produce high-efficiency batteries.The development of clean and efficient silicon-based materials is of vital significance to the improvement of the whole energy system.In the experiment,the emergence of oxygen by molten salt electrolysis method for the preparation of silicon alloy,by investigating the main pressure factors in the pressing process of the pre-electrolytic material,12 MPa was obtained at the optimum sheet pressure.Then,an electric deoxidation experiment with different time gradients at 850 °C was carried out.The SEM microstructure observation and XRD crystal structure analysis of different gradient products were carried out,and the impurity phase was gradually reacted with the electrolysis time to finally obtain a silicon-based alloy without other impurities.The time for the Si-Mn alloy to obtain a pure alloy was 38 h;the optimum electrolysis time for the Si-Ni alloy was 10 h.In addition,the optimal time structure was obtained for further TEM test to confirm the experimental results.After the obtained silicon-based alloy material was subjected to washing,acidification and vacuum drying,a series of treatments were performed.The material was ground and assembled with a binder and a conductive agent in a ratio of 8:1:1,and the button cell assembly was uniformly stirred and subjected to relevant electrochemical performance tests.When the Si-Mn alloy has a current density of 100 m A?g^-1 initial specific capacity is 1374.5 m Ah?g^-1,after 110 cycle specific capacities is 682 m Ah?g^-1,the retention rate is 49.6%,and after cyclic coulomb efficiency has kept more than 98.5%.And Si-Ni alloy in the current density was 100 m A?g^-1 initial specific capacity is 170.8 m Ah?g^-1,after 410 cycles,the specific capacity is 124.7 m Ah?g^-1,and the retention rate is 73%.After more than 400 cycles,the coulomb efficiency has been steadily maintained at over 98.5%.After the test,the specific capacity of the material presented the same trend as that of the circulation with the increase of current density.After the test,material was tested again under small current.The performance was basically consistent with the specific capacity under the same current density as showed in the previous multiplier performance diagram,indicating that the material had good circulation stability.Figure 45;table 2;Reference 110...