【摘要】 采用两步固相法,在交替气氛煅烧(空气预烧,氮气煅烧)下合成了尖晶石钛酸锂粉末,并且研究了煅烧气氛(空气和氮气)对不同合成阶段(预烧和煅烧)的影响。电化学测试结果表明,经空气预烧,氮气煅烧得到的样品在5 C的电流密度下,首次充电比容量高达128 m Ah/g,100次循环后容量保持率达94.5%,其电化学性能明显优于单一气氛煅烧下所得样品。分析其原因为碳酸锂的分解反应在空气气氛下较氮气气氛下更容易进行,且氮气气氛下合成LTO有氧空位的存在。更多还原

【Abstract】 Spinel Li4Ti5O12(LTO) powders were prepared in a novel alternate atmosphere(first preheated in air, then calcined in nitrogen) by two-step solid state method. The influence of calcination atmosphere(air and nitrogen) on the different stages of synthesis process(precalcination and calcination process) was systematically investigated.The electrochemical test results show that sample prepared in an alternate atmosphere delivers an initial charge specific capacity of 128 m Ah/g with a capacity retention of 94.5% after 100 cycles at 5 C and exhibits better electrochemical performance than the sample at a single atmosphere of air or nitrogen. It can be ascribed to the easier occurred decomposition of Li2CO3 in air and oxygen vacancies generated in low-oxygen partial pressure atmosphere(nitrogen).更多还原