排序方式: 共有77条查询结果,搜索用时 62 毫秒
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以Li2CO3,NH4H2PO4,V2O5和MoO3为原料,柠檬酸为络合剂和碳源,采用溶胶凝胶法制备了锂离子正极材料Li3MoxV2-x(PO4)3/C (x = 0.01, 0.02和0.03). X射线衍射(XRD)表明,合成的材料具有单一的单斜晶系结构,空间群为P21/n. 扫描电镜(SEM)显示Li3Mo0.02V1.98(PO4)3/C具有均一的表面形貌。恒流充放电测试表明,当x = 0.02时,掺杂后的Li3Mo0.02V1.98(PO4)3具有最佳的电化学性能. 在1C倍率下,3.0 ~ 4.3 V电位区间,Li3Mo0.02V1.98(PO4)3/C的首次放电比容量达到122.3 mAh?g-1,循环50周之后,容量没有衰减的迹象;而当x = 0, 0.01和0.03时,首次放电比容量仅分别为117.1 mAh?g-1,115.1 mAh?g-1和116.0 mAh?g-1. 在3C和5C倍率下,样品Li3Mo0.02V1.98 (PO4)3/C仍能保持优异的循环稳定性. 相似文献
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A mathematic model is used to describe the mass transfer of mulfticomponents [O2, H2O(g), N2] in the gas diffusion layer of air electrodes of phosphoric acid fuel cells (PAFC). A program of solving this mathematic model is designed with FORTRAN77. The main factors effecting the efficiency of mass transfer in gas diffusion layer are predicted by means of the numberical analysis of the proposed model. The range of these fartors allowed to change is also determined. 相似文献
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