Effects of Thermal Annealing on the Li+ Intercalation Properties of V2O5·nH2O Xerogel Films
Effects of Thermal Annealing on the Li+ Intercalation Properties of V2O5·nH2O Xerogel Films
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DOI：
10.1021/jp051275
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发表时间：
2005-05
影响因子：
3.3
通讯作者：
Ying Wang;H. Shang;T. Chou;G. Cao
中科院分区：
文献类型：
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作者：
Ying Wang;H. Shang;T. Chou;G. Cao
采用溶胶-凝胶法制备了n = 1.6，0.6和0.3的V2 O 5·nH 2 O干凝胶薄膜，通过V2 O 5与H2 O2反应，然后在环境条件下干燥，并分别在110和250 °C下热退火。脱水后，V2 O 5在300−330 °C下结晶，如热重分析和X射线衍射所示。电化学性能测试表明，V2 O 5·0. 3 H2O薄膜具有最好的嵌锂性能，在100 μA/cm 2的高电流密度下，50次循环后的初始容量为275 mAh/g，稳定容量为185 mAh/g。在10 μA/cm 2的低电流密度下，该薄膜的容量可达390 mAh/g。这种增强的电化学性能通过热处理归因于减少的水含量，保留的层间距，和占主导地位的非晶相在膜中。
V2O5·nH2O xerogel films with n = 1.6, 0.6, and 0.3 have been prepared from the sol−gel route by reacting V2O5 with H2O2 followed by drying under ambient conditions and thermal annealing at 110 and 250 °C, respectively. After dehydration, V2O5 crystallizes at 300−330 °C, as revealed by thermal gravimetric analysis and X-ray diffraction. Electrochemical characterization demonstrated that V2O5·0.3H2O film exhibits the best Li+ intercalation performance, with an initial capacity of 275 mAh/g and a stabilized capacity of 185 mAh/g under a high current density of 100 μA/cm2 after 50 cycles. Under a low current density of 10 μA/cm2, the capacity of this film can reach 390 mAh/g. Such an enhanced electrochemical property by thermal treatment is ascribed to the reduced water content, the retained interlayer spacing, and the dominant amorphous phase in the film.