2019 Volume 62 Issue 1 Pages 15-20
It has been one of the key issues to understand the lithium transport in the cathodic materials during the lithium ion battery operation at high charge-discharge rate. Operando transmission electron microscope (TEM) observation is a power method to solve this problem, since such dynamics has been suggested to be a kind of nonequilibrium behaviors. We developed nanobatteries consisting of LiMn2O4 nanowires cathode, liquid ion electrolyte and Li4Ti5O12 crystalline anode for operando TEM observation. By taking electron diffraction patterns of the cathode in the vicinity of the interface, we found that the cubic phase of the LiMn2O4 nanowire changed into two phases of the cubic and orthorhombic phases and finally into the tetragonal phase during discharging process. It suggests that a lot of lithium ions must be accumulated in the vicinity of the interface with the electrolyte. We also investigated the lithium ion transport inside the nanowire cathode.