Department of Energy System, Pusan National University, Busan 609-735, Republic of Korea.
Global Core Research Center for Ships and Offshore Plants (GCRC-SOP), Pusan National University, Busan 609-735, Republic of Korea.
Sci Rep. 2014 Mar 12;4:4350. doi: 10.1038/srep04350.
Li4Ti5O12 (LTO) is recognized as being one of the most promising anode materials for high power Li ion batteries; however, its insulating nature is a major drawback. In recent years, a simple thermal treatment carried out in a reducing atmosphere has been shown to generate oxygen vacancies (VO) for increasing the electronic conductivity of this material. Such structural defects, however, lead to re-oxidization over time, causing serious deterioration in anode performance. Herein, we report a unique approach to increasing the electronic conductivity with simultaneous improvement in structural stability. Doping of LTO with Mo in a reducing atmosphere resulted in extra charges at Ti sites caused by charge compensation by the homogeneously distributed Mo(6+) ions, being delocalized over the entire lattice, with fewer oxygen vacancies (VO) generated. Using this simple method, a marked increase in electronic conductivity was achieved, in addition to an extremely high rate capability, with no performance deterioration over time.
钛酸锂（Li4Ti5O12，LTO）被认为是最有前途的高功率锂离子电池正极材料之一；然而，其绝缘性质是一个主要的缺点。近年来，在还原气氛下进行的简单热处理已被证明可以产生氧空位（VO），从而提高这种材料的电子导电性。然而，这种结构缺陷会随着时间的推移而重新氧化，导致阳极性能严重恶化。在此，我们报告了一种独特的方法，可以在提高电子导电性的同时提高结构稳定性。在还原气氛中掺杂 LTO 中的 Mo 会导致 Ti 位上的额外电荷，这是由均匀分布的 Mo(6+)离子的电荷补偿引起的，这些 Mo(6+)离子在整个晶格中离域，产生的氧空位（VO）较少。使用这种简单的方法，除了极高的倍率性能外，电子电导率也得到了显著提高，而且随着时间的推移没有性能下降。
