欢迎访问过程工程学报, 今天是

过程工程学报 ›› 2024, Vol. 24 ›› Issue (9): 1080-1087.DOI: 10.12034/j.issn.1009-606X.223365CSTR: 32067.14.jproeng.223365

• 研究论文 • 上一篇    下一篇

SiO/C浆料稳定性及半干法匀浆工艺研究

刘峰*， 卢诚   

  1. 天津捷威动力工业有限公司，天津 300380
  • 收稿日期:2023-12-28 修回日期:2024-03-18 出版日期:2024-09-28 发布日期:2024-09-23
  • 通讯作者: 刘峰 jevelf@163.com

Study on stability of SiO/C slurry and semi-dry homogenization process

Feng LIU*,  Cheng LU   

  1. Tianjin EV Energies Co., Ltd., Tianjin 300380, China
  • Received:2023-12-28 Revised:2024-03-18 Online:2024-09-28 Published:2024-09-23

RichHTML

PDF

摘要： 硅负极因其极高的比容量成为高能量密度锂电池的研究热点，目前硅氧已实现批量生产和应用。锂离子电池的性能、寿命和一致性与其电极性能直接相关，匀浆是电极生产中的关键工序。本工作研究了硅氧碳负极(SiO/C)浆料的稳定性并考察了半干法匀浆工艺，对比了碳含量分别为1.6wt%和3.1wt%的SiO/C-1和SiO-2在水系浆料中的稳定性。SiO/C-1在水中产气明显，原因为Si在碱性条件下与H2O反应生成H2，而SiO/C-2浆料无产气，浆料和极片状态较好。SEM, EDS, TEM等表征结果表明SiO/C-2表面存在厚度20~30 nm均匀的碳包覆层，可阻隔水分并提高稳定性。为提高硅负极浆料稳定性并提高匀浆效率，研发了半干法匀浆工艺，对浆料固含率、黏度、细度、流变、产气等参数进行了测试，对极片剥离力、电阻、电镜下的微观形貌以及电池循环性能进行了考察，结果表明优化后的半干法匀浆工艺制得的浆料固含量为51.8wt%，黏度为4900 mPa?s，细度为20 μm，浆料静置24 h后黏度为10 000 mPa?s，浆料48 h基本无产气，制作负极片剥离力为15 N/m，电阻率为0.106 Ω/cm，搭配高镍NCM(Ni9)制作的330 Wh/kg软包电池高温循环寿命可达800周，明显优于普通湿法工艺。

关键词: 锂离子电池, 硅氧碳负极, 负极浆料, 匀浆工艺

Abstract: 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 10 000 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.

Key words: lithium-ion battery, SiO/C anode, anode slurry, homogenization process