Energy-Density Improvement in Li-Ion Rechargeable Batteries Based on LiCoO + LiVO and Graphite + Li-Metal Hybrid Electrodes.

We developed a novel battery system consisting of a hybrid (LiCoO + LiVO) cathode in a cell with a hybrid (graphite + Li-metal) anode and compared it with currently used systems. The hybrid cathode was synthesized using various ratios of LiCoO:LiVO, where the 80:20 wt% ratio yielded the best electrochemical performance. The graphite and Li-metal hybrid anode, the composition of which was calculated based on the amount of non-lithiated cathode material (LiVO), was used to synthesize a full cell. With the addition of LiVO, the discharge capacity of the LiCoO + LiVO hybrid cathode increased from 142.03 to 182.88 mA h g (a 28.76% improvement). The energy density of this cathode also increased significantly, from 545.96 to 629.24 W h kg (a 15.21% improvement). The LiCoO + LiVO hybrid cathode was characterized through X-ray diffraction analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Its electrochemical performance was analyzed using a battery-testing system and electrochemical impedance spectroscopy. We expect that optimized synthesis conditions will enable the development of a novel battery system with an increase in energy density and discharge capacity.