The influence of Li2O incorporation on the electrochemical properties of Li4Ti5O12 thin film electrodes

Abstract

High quality Li4Ti5O12 anode films were deposited by radio-frequency co-sputtering Li4Ti5O12 and Li2O targets on Pt-coated stainless steel substrates. The use of an additional Li2O target not only compensated the lithium content in the resulting layers but also decreased the impurity content. Consequently, the electrochemical properties of the Li4Ti5O12 anode exhibited better electrochemical properties than an identical film prepared using a single Li4Ti5O12 target. Upon annealing, the co-sputtering Li4Ti(5)O(12) showed a relatively high discharge capacity of 618 mAh/cm(3)(theoretical specific capacity of 598.5 mAh/ cm(3)) at a current density of 0.1 C. Also, superior high rate capability with a discharge capacity of 309 mAh/cm(3) at 20 C was observed, accompanied by an excellent cycling stability, with a capacity retention ratio exceeding 94% after 500 cycles at 1 C. The co-sputtering using Li2O target is most likely to have enhanced the electrochemical properties of the pure Li4Ti5O12 anode. (C) 2019 Elsevier B.V. All rights reserved.