Abstract A series of Cr-doped Li3V2-xCrx(PO4)3/C (x = 0.00, 0.10, 0.15, 0.20) composites was synthesized using Sol-gel method. The influence of Cr doping on the structure, morphology and electrochemical performance of Li3V2(PO4)3/C were studied. The X-ray diffraction patterns indicate that all of the samples are consistent with those of monoclinic Li3V2(PO4)3, indicating that Cr3+ can be successfully doped into the lattice of Li3V2(PO4)3. Scanning electron microscopy, transmission electron microscopy mages revealed the morphology and the uniform distribution of Cr in the samples. In the potential range of 3.0–4.3 V, the Li3V1.9Cr0.1(PO4)3/C composite exhibited the highest discharge capacity of 125.1 mAh/g at 0.1 C, while the Li3V1.8Cr0.2(PO4)3/C performed a capacity of 95.8 mAhg−1 with a high capacity retention ratio of 91.6% after 40 circles, which is still lower than the capacity of the Li3V1.9Cr0.1(PO4)3/C. Based on the excellent electrochemical performance, Li3V1.9Cr0.1(PO4)3/C will be a promising cathode material for rechargeable lithium-ion batteries.

中文翻译：

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锂离子电池用Cr掺杂Li3V2(PO4)3/C正极材料的合成及性能

摘要 采用溶胶-凝胶法合成了一系列Cr掺杂的Li3V2-xCrx(PO4)3/C (x = 0.00, 0.10, 0.15, 0.20)复合材料。研究了Cr掺杂对Li3V2(PO4)3/C的结构、形貌和电化学性能的影响。X射线衍射图表明所有样品与单斜晶Li3V2(PO4)3一致，表明Cr3+可以成功地掺杂到Li3V2(PO4)3的晶格中。扫描电子显微镜、透射电子显微镜图像揭示了样品中 Cr 的形态和均匀分布。在 3.0–4.3 V 的电位范围内，Li3V1.9Cr0.1(PO4)3/C 复合材料在 0.1 C 时表现出最高的放电容量，为 125.1 mAh/g，而 Li3V1.8Cr0.2(PO4)3/C 40 圈后容量保持率为 95.8 mAhg-1，容量保持率为 91.6%，仍低于 Li3V1.9Cr0.1(PO4)3/C 的容量。基于优异的电化学性能，Li3V1.9Cr0.1(PO4)3/C 将成为一种很有前途的锂离子电池正极材料。