Using copper acetylacetonate as an additive to greatly improve the high rate performance of the commercial lithium titanate

For the first time, it is discovered that copper acetylacetonate (denoted as Cu(acac) 2 ) can be employed as an additive to significantly improve the long-term high rate performance of the commercial lithium titanate (Li 4 Ti 5 O 12 , LTO) through sintering a tablet containing LTO and Cu(acac) 2 . In this work, firstly, a mixture containing LTO and Cu(acac) 2 with a Ti to Cu molar ratio of 5:2 is pressed into a tablet, and then, the resultant tablets are sintered in air at three different temperatures. The specimens sintered at 510°C, 610°C and 710°C are nominated as material a, b and c, respectively. And, LTO and CuO, as revealed by the XRD and XPS tests, are indicated to be the main components of all the sintering products. Above all things, as verified by the results of GCD (galvanostatic charge-discharge) experiments, the battery performances of all the sintering products are much better than that of the pure LTO (material o). In particular, the long-term high rate performances of all resultant materials are significantly superior to that of the commercial LTO, for instance, the discharge capacities tested at 20C after 500 cycles are about 46, 72 and 62 mAh g -1 of material a, b and c, respectively, being about 1.2, 1.9 and 1.6 times that of the commercial LTO (38 mAh g -1 ). The significantly reduced charge transfer resistance (R ct ) as well as the improved reversibility of Li + insertion and extraction process is analyzed to be the principal reasons giving all prepared materials, especially material b, an excellent long-term high rate performance. Preparing a novel lithium ion batteries (LIBs) anode material of CuO-containing LTO and showing a new approach to greatly enhance the long-term high rate performance of LTO are two main dedications of this preliminary work, which is very helpful to the further exploration of LTO.