Posted: Dec 07, 2015 |
Basic technology of high thermally-durable all-solid-state lithium ion battery developed
(Nanowerk News) This technology is significant as it allows the thermally durable Li-ion battery to be used in a wider variety of applications, such as large-scale industrial machines with motors, and medical machines which need to be heated for autoclave sterilization. Since this technology does not require the cooling system common in conventional Li-ion batteries, it is expected to lead to further developments of compact battery systems and reduce overall costs.
|
The high energy density Li-ion battery is already being used as power sources in applications such as portable devices (smartphones and tablets), electric vehicles and adjustor of the supply and demand of renewable energy.
|
The conventional Li-ion battery consists of a separator, a positive electrode layer and a negative electrode layer (Fig.1 (a)). The battery is filled with organic electrolyte solution in which lithium ion conducts between the two electrode layers during the charge and discharge process.
|
|
This is a schematic illustration of lithium ion battery (LIB). (click on image to enlarge)
|
An issue of the conventional Li-ion battery, with the organic electrolyte solution, is thermal durability. The upper operating temperature is limited to around 60°C owing to volatility of the organic electrolyte solution. Consequently, it is difficult to use the conventional Li-ion battery in a high temperature environment without a cooling system.
|
Therefore, the solid electrolyte with no volatility has been developed for the utilization of Li-ion battery in a high temperature environment. The lithium ion conductivity of solid electrolyte, however, is lower than that of the organic electrolyte solution, and the internal resistance of all-solid-state Li-ion battery should be reduced for its commercialization.
|
Prof. Shin-ichi Orimo's lab in AIMR and the Institute for Material Research at Tohoku University have been conducting research on LiBH4-based complex hydrides as novel and solid electrolytes. They have confirmed the fast lithium ion conductivity in the wide temperature range from room temperature to 150°C.
|