Study on stability of SiO/C slurry and semi-dry homogenization process
Si based anode has become a research hotspot for high energy density lithium batteries due to its high specific capacity,and the preliminary production and application of SiO has been realized.The electrical performance,lifetime and consistency of lithium-ion battery are directly related to its electrode performance,and homogenization is a key process in the electrode production.The stability of SiO/C anode slurry was studied and a semi-dry homogenization process was innovatively developed.The stability of SiO/C-1 and SiO-2 with 1.6wt％and 3.1wt％of carbon was compared in aqueous slurry,and the gas production of SiO/C-1 was obvious in the water due to the fact that Si reacted with H2O to form H2 under alkaline condition,while there was no gas production of SiO/C-2,and the condition of the slurry and the electrode was better.SEM,EDS,and TEM showed that SiO/C-2 had a uniform carbon coating layer with a thickness of 20～30 nm,which can block water and improve the stability,and in the application of SiO/C,it was necessary to pay attention to the carbon coating of the material.In order to improve the stability of SiO/C anode electrode slurry to improve the homogenization efficiency,a semi-dry homogenization process was developed,through the testing of slurry solid content,viscosity,fineness,rheology,gas production and the peeling force,resistance of the electrode,SEM,as well as the cycling performance of the cell was analyzed.The results showed that the developed semi-dry homogenization process was able to achieve a high solid content of 51.8wt％,viscosity of 4900 mPa·s and fineness of 20 μm.The viscosity of the slurry was 10000 mPa·s after 24 h,and the slurry was basically free of gas production for 48 h.The peeling force of the anode electrode was 15 N/m,and the resistivity was 0.106 Ω/cm.The high-temperature cycle life of the 330 Wh/kg pouch cell made with high-nickel NCM(Ni9)can reach 800 cycles,which was obviously superior to that of the ordinary wet homogenizing process.
lithium-ion batterySiO/C anodeanode slurryhomogenization process
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