Department of Materials Science and Engineering, Jinzhong University, Jinzhong 030619, China.
Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China.
Molecules. 2023 Apr 20;28(8):3595. doi: 10.3390/molecules28083595.
Biomass-derived hard carbon materials are considered as the most promising anode materials for sodium-ion batteries (SIBs) due to their abundant sources, environmental friendliness, and excellent electrochemical performance. Although much research exists on the effect of pyrolysis temperature on the microstructure of hard carbon materials, there are few reports that focus on the development of pore structure during the pyrolysis process. In this study, corncob is used as the raw material to synthesize hard carbon at a pyrolysis temperature of 1000~1600 °C, and their interrelationationship between pyrolysis temperature, microstructure and sodium storage properties are systematically studied. With the pyrolysis temperature increasing from 1000 °C to 1400 °C, the number of graphite microcrystal layers increases, the long-range order degree rises, and the pore structure shows a larger size and wide distribution. The specific capacity, the initial coulomb efficiency, and the rate performance of hard carbon materials improve simultaneously. However, as the pyrolysis temperature rises further to 1600 °C, the graphite-like layer begins to curl, and the number of graphite microcrystal layers reduces. In return, the electrochemical performance of the hard carbon material decreases. This model of pyrolysis temperatures-microstructure-sodium storage properties will provide a theoretical basis for the research and application of biomass hard carbon materials in SIBs.
生物质衍生的硬碳材料由于其丰富的来源、环境友好性和优异的电化学性能，被认为是最有前途的钠离子电池 (SIBs) 负极材料。尽管有大量关于热解温度对硬碳材料微观结构影响的研究，但很少有报道关注热解过程中孔结构的发展。本研究以玉米芯为原料，在 1000~1600°C 的热解温度下合成硬碳，并系统研究了它们的热解温度、微观结构和储钠性能之间的关系。随着热解温度从 1000°C 升高到 1400°C，石墨微晶层数增加，长程有序度提高，孔结构呈现较大的尺寸和较宽的分布。硬碳材料的比容量、初始库仑效率和倍率性能均得到提高。然而，当热解温度进一步升高到 1600°C 时，类石墨层开始卷曲，石墨微晶层数减少。相应地，硬碳材料的电化学性能下降。这种热解温度-微观结构-储钠性能的模型将为生物质硬碳材料在 SIBs 中的研究和应用提供理论依据。
