Electrochemical lithium intercalation into WO3 and lithium tungstates Lix WO3+x /2 of various structures
Electrochemical lithium intercalation into WO3 and lithium tungstates Lix WO3+x /2 of various structures
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DOI：
10.1007/s100080050116
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发表时间：
1998-10
影响因子：
2.5
通讯作者：
A. Yu;N. Kumagai;Zhaolin Liu;J. Lee
中科院分区：
文献类型：
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作者：
A. Yu;N. Kumagai;Zhaolin Liu;J. Lee
采用软化学法制备了六方和单斜钨氧化物WO_3和六方钨酸锂LixWO_3+x/2(x= 0.10-0.42)作为二次锂电池的正极材料。六方结构，无论是氧化物还是钨酸盐，在Li+插层反应中都表现出比容量高和循环性能好的单斜晶型。六方钨酸盐中预先分配的锂(如Li2O)的存在降低了锂的插层容量。此外，无水钨酸盐的开路电压(OCV)与插层深度(N)的关系曲线显示出两条斜率不同的直线，这可能与锂插层的结构变化有关。锂在主体结构中的有效扩散系数D˜也与这些化合物的结构和组成有关。
Hexagonal and monoclinic tungsten trioxides WO3and hexagonal lithium tungstates LixWO3+x/2(x= 0.10–0.42) from a soft chemistry route were used as the active cathode material in secondary lithium batteries. The hexagonal structures, regardless of their being an oxide or a tungstate, showed higher specific capacities and better cycling behavior in Li+intercalation reactions than the monoclinic form. The presence of pre-allocated lithium (as Li2O) in hexagonal tungstates decreased the capacity for lithium intercalation. Additionally, the plot of open-circuit voltage (OCV) against the depth of intercalation (n) for anhydrous tungstates showed two straight lines with different slopes that can be related to the structural changes in lithium intercalation. The effective diffusion coefficients of lithium insertion into the host structure,D˜, were also found to be dependent on the structure and the composition of these compounds.