Li4 Ti5 O12 Anode: Structural Design from Material to Electrode and the Construction of Energy Storage Devices.

ABSTRACT

Spinel Li4 Ti5 O12 , known as a zero-strain material, is capable to be a competent anode material for promising applications in state-of-art electrochemical energy storage devices (EESDs). Compared with commercial graphite, spinel Li4 Ti5 O12 offers a high operating potential of ∼1.55 V vs Li/Li+ , negligible volume expansion during Li+ intercalation process and excellent thermal stability, leading to high safety and favorable cyclability. Despite the merits of Li4 Ti5 O12 been presented, there still remains the issue of Li4 Ti5 O12 suffering from poor electronic conductivity, manifesting disadvantageous rate performance. Typically, a material modification process of Li4 Ti5 O12 will be proposed to overcome such an issue. However, the previous reports have made few investigations and achievements to analyze the subsequent processes after a material modification process. In this review, we attempt to put considerable interest in complete device design and assembly process with its material structure design (or modification process), electrode structure design and device construction design. Moreover, we have systematically concluded a series of representative design schemes, which can be divided into three major categories involving (1) nanostructures design, conductive material coating process and doping process on material level; (2) self-supporting or flexible electrode structure design on electrode level; (3) rational assembling of lithium ion full cell or lithium ion capacitor on device level. We believe that these rational designs can give an advanced performance for Li4 Ti5 O12 -based energy storage device and deliver a deep inspiration.