Preparation Of Highly Conductive Carbon Black And Its Application In Lithium Ion Batteries

Carbon Black（CB）is the most used conductive additive in the commercial application of lithium-ion batteries.However,the research on conductive carbon black in China is still in the initial stage,and the situation that high conductive carbon black is monopolized by foreign technology in the market for a long time needs to be reversed in order to realize the rapid development of lithium-ion batteries.In this paper,three types of carbon blacks with different structures and conductive properties were prepared by graphitization,oxidation and synergistic modification of the two as raw materials,and then used as conductive additives in lithium-ion batteries to study the effects of different structures and conductive carbon blacks on the performance of lithium-ion batteries,with the aim of providing solutions to the problem of the gap in the domestic market of high conductive carbon blacks for lithium-ion batteries.The research content is as follows:In the first part,a series of highly conductive carbon blacks with different structures were obtained by adjusting the process method of preparation.First,the conductive properties and structures of several commercial carbon blacks were analyzed.The data showed that the structural characteristics of carbon blacks such as high structure,low defect density,large graphite flake layer,and high purity are beneficial to improve the electrical conductivity of carbon blacks.Then,the graphitization（G）,oxidation（O）and"graphitization-CO₂oxidation"synergistic treatment（GO）were carried out on the ordinary carbon black N134 to obtain high graphitization carbon black,high specific surface area carbon black,carbon black with special The electrical conductivity can be increased up to 2.7 times,2.5 times and 7.5 times of the original material respectively.Among them,the conductivity of carbon black after"GO"method is higher than that of foreign ultra-high conductivity carbon black ECP-300JD,which has strong engineering application value.In the second part,commercial carbon blacks and homemade carbon blacks were assembled as conductive additives to obtain lithium-ion batteries.In this paper,the battery assembled with 10%proportion of conductive carbon black has the highest discharge specific capacity and the best cycling stability compared to 5%and 7%.In comparison with the batteries assembled by different types of commercial carbon blacks,the batteries assembled by carbon blacks with high conductivity,high structure and high crystallinity have better specific capacity,cycling stability performance and multiplicity performance.The performance of cells assembled with a series of self-made carbon blacks as conductive agents has been improved to different degrees.Among them,the battery assembled by CB-GO as the conductive agent has the most excellent overall performance,indicating that CB-GO has good application value in lithium-ion batteries.Moreover,it is further demonstrated that the moderate specific surface area,ordered graphite microcrystalline structure and large graphite flake layer have a positive effect on the performance of the battery.