2018-02-03 - High-voltage cathode material enables production of low-cost, cobalt-free lithium rechargeable batteries

Fujitsu Laboratories Ltd. has announced it has successfully developed a cathode material for lithium iron phosphate rechargeable batteries. This new material offers high voltage that could only be achieved by cobalt-based materials in the past.

Currently, the rare metal cobalt is a component of cathodes in high capacity and high-voltage lithium rechargeable batteries for electric vehicles (EVs) and home storage batteries. As these devices become more popular, there are concerns regarding future shortages of cobalt used in rechargeable lithium-ion batteries. Significant cost increases are also expected, generating interest in abundant and cheap iron to replace cobalt as the constituent element in rechargeable batteries. However, iron could not offer voltage comparable to that of cobalt-based materials.

Now the company has discovered a new factor that can improve the voltage of iron-based materials. Using a proprietary materials design technology as well as a technology that precisely controls the composition of raw materials and the formation process of materials, their laboratories have successfully synthesized lithium iron pyrophosphate. This phosphate-based material has a voltage of 3.8V, comparable to that of existing cobalt-based materials.

In the future, the company will seek to improve the performance of cathodes using this newly developed iron-based material. By advancing the design of new crystal structures that can maintain a high voltage state for longer periods, it aims to develop cathode materials that offer high energy density comparable to cobalt-based materials. In this way, it will contribute to lowering the cost of lithium rechargeable batteries and the devices that use them.