| Sol-gel法制备的LiTi2-xMnx(PO4)3@C复合纳米材料及其储锂性能 |
| Sol-gel Synthesis of LiTi2-xMnx(PO4)3@C Composite Nanoparticles as a Superior Cathode Material for Lithium-Ion Batteries |
|
| 摘要: 通过简单的溶胶-凝胶方法成功合成一系列Nasicon型LiTi2-xMnx（PO4）3@C（x=0.02，0.05，0.08和0.1）。掺入异价元素锰增大了LiTi2（PO4）3的晶格参数，从而扩大Li+的传输通道，并降低了电化学阻抗。同时材料的表面包覆均匀的导电碳层以提高电子的传输速率。所有复合材料通过粉末X射线衍射仪及透射电子显微镜进行表征。LiTi1.92Mn0.08（PO4）3@C作为锂离子电池正极材料表现出最佳的电化学性能。在0.1C倍率下，电池循环150次后放电容量高达145 mAh·g-1，增大至5C倍率下首次充放电达到132 mAh·g-1。优异的电化学性能可归因于掺杂提高了锂离子扩散系数及包覆碳材料降低了传荷阻抗。 |
| 关键词: 掺杂 碳包覆 溶胶-凝胶法 正极材料 电化学性能 |
| 基金项目: 国家自然科学基金（No.21701079，21801109），山东省自然科学基金（No.ZR2017BB016，ZR2018BB019），大学生创新创业训练计划项目（No.201910452010）和山东省本科教改项目（Z2018S006）资助。 |
| Abstract: A Nasicon-type LiTi2-xMnx(PO4)3@C (x=0.02, 0.05, 0.08 and 0.1) has been successfully synthesized by a simple sol-gel method. The precipitates were annealed at 700℃ for 10 h in Ar. The metallic ion doping could increase their lattice parameters, along with the large available tunnels for Li+ diffusion, and then decrease the electrochemical resistance. The carbon layer plays an important role in improving the electronic conductivity. These composites were characterized via powder X-ray diffractometry with Cu Kα line as a radiation (λ=0.154 18 nm). The morphologies were observed by a transmission electron microscopy. The molar ratio of nMn:nTi was obtained from ICP-AES analysis. Among the samples, LiTi1.92Mn0.08(PO4)3@C exhibited the best electrochemical performance as a cathode material for lithium ion batteries, with a discharge capacity of 145 mAh·g-1 after 150 cycles at 0.1 C. It even delivered a discharge capacity of 132 mAh·g-1 in the first cycle at 5 C. This superior electrochemical property could be ascribed to its enhanced lithium-diffusion induced by doping and improved electronic conductivity induced by carbon coating. |
| Keywords: doping carbon coating sol-gel method cathode material electrochemical performance |
| 投稿时间：2019-06-11 修订日期：2020-01-08 |
| 摘要点击次数: 1197 |
| 全文下载次数: 421 |
| 夏宗梅,胡芳东,胡语清,赵萌,张雪梅,姜晓蕾.Sol-gel法制备的LiTi2-xMnx(PO4)3@C复合纳米材料及其储锂性能[J].无机化学学报,2020,36(4):620-626. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
| Support information: |
|
|
|
|
|
|
