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以纳米二氧化锡、硝酸钴、脲、葡萄糖和十二烷基硫酸钠为原料,通过水热-碳热还原原位制备锂离子电池Sn-Co-C复合负极材料。通过XRD、SEM、EDS和TEM分析表明,原位生成的Sn-Co合金颗粒分布于纳米或微米尺度的碳球和碳纳米棒内部以及微孔碳基体之中。电化学测试表明,在50 m A·g-1电流密度下,Sn-Co-C复合负极材料首次充放电比容量分别为602.9 m Ah·g-1和867.1 m Ah·g-1,循环100次后其充放电比容量仍分别保持在350.4 m Ah·g-1和356.6 m Ah·g-1,平均每次放电容量衰减率仅为5.1%。优异的电化学性能主要归因于Sn-Co合金颗粒处于纳米或微米尺度的碳球和碳纳米棒内部以及微孔碳基体之中可以改善其导电性,并可以缓解锂电池充放电过程中产生的体积变化所导致的活性物质脱落,提高循环性能和寿命。
Sn-Co-C composite negative electrode material was prepared in situ by hydrothermal-carbothermal reduction using nano-tin dioxide, cobalt nitrate, urea, glucose and sodium lauryl sulfate as raw materials. The results of XRD, SEM, EDS and TEM show that the Sn-Co alloy particles generated in situ are distributed in the carbon and carbon nanorods and the microporous carbon matrix on the nanometer or micrometer scale. The results of electrochemical tests showed that the initial charge-discharge capacity of Sn-Co-C composite cathode materials was 602.9 m Ah · g-1 and 867.1 m Ah · g-1 at the current density of 50 m A · g-1, respectively. The charge and discharge capacities remained at 350.4 m Ah · g-1 and 356.6 m Ah · g-1, respectively, with an average of 5.1% decay rate per discharge. Excellent electrochemical performance is mainly due to the Sn-Co alloy particles in nanoscale or micrometer scale carbon ball and carbon nanorods inside and microporous carbon matrix can improve its conductivity, and can alleviate the lithium battery charge and discharge process generated The volume of the resulting changes in the active material off, improve cycle performance and life expectancy.