Development of lithium ion battery using fiber-type lithium-rich cathode and carbon anode materials

Abstract A lithium ion battery is developed using fiber-type Li-rich cathode and carbon anode materials. The cathode material is synthesized onto the carbon fiber by a two-step reaction process, namely, the electrodeposition for forming the precursor and the hydrothermal treatment for synthesizing the active material. The active material layer is composed of nanoparticles, which can be identified as a 94.8 wt.% primary Li₂MnO₃ phase together with a 5.2 wt.% minor Li₄Mn₅O₁₂ phase based on a synchrotron X-ray diffraction analysis. This cathode possesses a typical irreversible capacity during the first charge/discharge cycle, which can be utilized to compensate for the anode one, enabling the full cell to work without an initial predoping. In addition, the cell exhibits a rapid activation, favorable coulomb efficiency and high-rate performance, suggesting that the fiber-type electrodes are structurally beneficial for the electrical conduction and ion diffusion. On the other hand, its discharge capacity fades with cycling, which can be attributed to the phase transformation from the layered Li₂MnO₃ to the spinel LiMn₂O₄.