CAJ | 학술논문

以Li_2CO_3和TiO_2为原料,固相法合成了不同Li_2CO_3过量的Li_4Ti_5O_(12)(简称LTO),通过X射线衍射法(XRD)对LTO相和残余TiO_2相的定量分析计算了合成纯的LTO所需Li_2CO_3原料过量程度.Li_2CO_3过量起到两方面的作用:(1)补充高温合成LTO过程中所挥发的锂,从而减少TiO_2含量;(2)造成一些Li+进入LTO晶格取代部分Ti~(4+),使得LTO的电导率增加,过多的取代量会降低LTO的比容量.这两种作用决定了Li_2CO_3过量对LTO的充放电性能具有显著影响,综合结果表明,Li_2CO_3过量5%所制备LITO具有最佳电化学储锂性能.
이Li_2CO_3화TiO_2위원료,고상법합성료불동Li_2CO_3과량적Li_4Ti_5O_(12)(간칭LTO),통과X사선연사법(XRD)대LTO상화잔여TiO_2상적정량분석계산료합성순적LTO소수Li_2CO_3원료과량정도.Li_2CO_3과량기도량방면적작용:(1)보충고온합성LTO과정중소휘발적리,종이감소TiO_2함량;(2)조성일사Li+진입LTO정격취대부분Ti~(4+),사득LTO적전도솔증가,과다적취대량회강저LTO적비용량.저량충작용결정료Li_2CO_3과량대LTO적충방전성능구유현저영향,종합결과표명,Li_2CO_3과량5%소제비LITO구유최가전화학저리성능.
Li_4Ti_5O_(12) (LTO) was synthesized by solid state reaction using Li_2CO_3 and TiO_2.The required degree of Li_2CO_3 for synthesizing pure LTO was calculated by XRD quantitative analysis.With the increase of excessive amount of Li_2CO_3,there were two factors influencing the properties of LTO:on the one hand,it compensated for the loss of Li~+ when synthesized at high temperature and then decreased the amount of TiO_2 existing in the LTO;on the other hand,Li~+ substituted for part of Ti~(4+) in LTO,this increased the conductivity of LTO and it would decrease the specific capacity when too much Ti~(4+) was substituted.The charge-discharge capacity was affected significantly by these two factors.The experiment results show that the most appropriate excessive amount of Li_2CO_3 is 5%.