Trang Nguyen Thi Hong, Ali Zahid, Kang Dae Joon
Department of Physics, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
ACS Appl Mater Interfaces. 2015 Feb 18;7(6):3676-83. doi: 10.1021/am508158v. Epub 2015 Feb 9.
We report on the excellent electrochemical response of lithium ion batteries that use a composite material comprised of mesoporous titanium dioxide (MTO) spheres and multiwalled carbon nanotubes (MWCNTs) for the anode. The composite structure was synthesized via a combined sol-gel and solvothermal method, and the batteries exhibited unprecedented discharge capacity, cycling stability, and reversibility when compared to those based on commercially available TiO2 nanopowders and mesoporous TiO2 spheres. The inclusion of the composite structure resulted in an improvement in electronic and ionic conductivity, a larger surface area, and a colossal number of open channels in the synthesized structure that allowed for lithium ion intercalation. We achieved a Coulombic efficiency of nearly 100% and a discharge capacity as high as 316 mA h g(-1) at a rate of C/5, which is 1.9 times higher than that which is practically attainable with TiO2. Moreover, we observed a capacity loss of only 3.1% after 100 cycles, which indicates that the synthesized structure has a highly stable nature.
我们报道了一种锂离子电池的优异电化学响应，该电池的负极使用了由介孔二氧化钛（MTO）球体和多壁碳纳米管（MWCNT）组成的复合材料。通过溶胶 - 凝胶和溶剂热法相结合合成了这种复合结构，与基于市售TiO2纳米粉末和介孔TiO2球体的电池相比，该电池展现出前所未有的放电容量、循环稳定性和可逆性。复合结构的加入提高了电子和离子导电性，增大了表面积，并在合成结构中形成了大量开放通道，有利于锂离子嵌入。我们在C/5的电流倍率下实现了近100%的库仑效率和高达316 mA h g(-1)的放电容量，这比使用TiO2实际可达到的容量高出1.9倍。此外，我们观察到在100次循环后容量损失仅为3.1%，这表明合成结构具有高度稳定性。
