本文以草酸锂、五氧化二钒、硼酸为原料,二水合草酸为碳源和还原剂,无水乙醇为分散剂,采用球磨法合成了Li_3V_2(BO_3)_3/C(LVB/C)复合材料前驱体,后经高温热处理得到LVB/C复合材料.采用TG-DTA技术对前驱体进行了热分析,通过XRD、SEM、EDS等技术研究了烧结条件对LVB/C材料的晶体结构、微观形貌、含碳量的影响.通过恒流充放电测试、循环性能测试、循环伏安测试和电化学阻抗测试等技术研究了烧结条件对LVB/C材料电化学性能的影响.电化学测试结果表明,800 o C下烧结10 h得到的样品电化学性能最佳,在50 mA·g~(-1)电流密度下,首次充放电比容量分别为427.6 mAh·g~(-1)和669.1 mAh·g~(-1),循环10次后,容量保持率分别为55.4%和35.2%.
【英文摘要】
The Li_3V_2(BO_3)_3/C(LVB/C) composite materials were successfully synthesized in two steps:Firstly, a stoichiomertric mixture of Li2 C2 O4, V_2O_5, H_3BO_3, H_2C_2O_4·H_2O and ethanol was thoroughly ball-milled to get the precursors. Secondly, the precursors were post-calcinated to get the ultimate products. The calcination temperatures of 750 oC, 800 oC and 850 oC were selected based on the TG-DTA analyses. The crystal structures, surface morphologies and carbon contents of the samples calcinated at five ...
【更新日期】
2018-05-21
【分类号】
TM912
【正文快照】
锂离子电池由于具有能量密度高、质量轻、安全环保、无记忆效应、便于携带等众多优点已经成为最受欢迎的新型储能器件[1].目前,商业化的锂离子电池负极材料石墨,尽管具有价格低廉、循环性能优异等优点,但其理论比容量仅为372 m Ah·g-1,对应的体积比容量仅为818 m Ah·m L-1[2]