Charge/discharge curves of the new cathode material. Black line: charge curve. Red line: discharge curve
FDK Corporation and Fujitsu Laboratories Ltd. have jointly developed lithium cobalt pyrophosphate (Li2CoP2O7) as a high-energy-density cathode material for all-solid lithium-ion batteries. The new material can operate at charge/discharge voltages of more than 5V, which is beyond the limits of conventional lithium secondary batteries.
While there is active progress on improving lithium-ion and other existing batteries, development work is advancing on various types of next-generation batteries with the potential to exceed the performance of existing batteries, and all-solid-state batteries are attracting attention as next-generation batteries with superior safety performance. FDK is working on the development of all-solid-state batteries, with such characteristics as high energy density, superior safety performance, and long battery life.
The energy of a battery is a function of its voltage and capacity, and the development of an electrode material with high voltage and high capacity is one of the requirements for a battery with high energy density.
In the process of developing an all-solid-state battery, through the use of FDK’s Computer Aided Engineering (CAE) technology and Fujitsu Laboratories’ materials formation technologies, FDK and Fujitsu Laboratories succeeded in developing the lithium cobalt pyrophosphate material. The material has approximately 1.5 times the energy density of existing cathode materials for lithium-ion batteries.
Comparison of the energy densities of the new cathode material versus conventional cathode materials. New Li2CoP2O7: 860 Wh/kg. Conventional LiFePO4: 530Wh/kg (actual available capacity). Conventional LiCoO2: 570Wh/kg (actual available capacity).
Through computational physics, FDK and Fujitsu Laboratories have found that this material, when applied to all-solid-state batteries, is capable of operating with twice the energy density of existing cathode materials used in lithium-ion batteries. While working to further raise the performance of this material, the companies will continue development with the aim of an early market launch of a compact and safe all-solid-state battery that can be used in IoT applications, wearables, and mobile devices.
FDK is using an inflammable oxide-based material as a solid electrolyte in advancing its development of all-solid lithium-ion batteries with superior safety performance.