Toyota Motor Corporation has developed the world's first method for observing the behaviour of lithium ions (Li-ions) in an electrolyte when a Li-ion battery charges and discharges which can provide crucial research for future developments.
By using this method, it is possible to observe in real-time, the deviation of Li-ions, one of the causes of deterioration in the performance of Li-ion batteries, said a statement from the company.
Toyota believes that this will provide essential guidelines for research and development (R&D) that aims to improve the performance and durability of batteries, which would lead to longer battery life, as well as longer driving ranges for plug-in hybrid vehicles (PHVs) and electric vehicles (EVs), it said.
Li-ion batteries use a metal oxide in the cathode, a carbon material in the anode, and an organic electrolyte for the electrolyte. Lithium ions flow in the electrolyte from the cathode to the anode when the battery is charging, and from the anode to the cathode when the battery is discharging, which results in an electric current flow. Thus, the Li-ions play an essential role within the electrolyte during battery charging and discharging.
It has been known that Li-ion deviation occurs in the electrodes and electrolyte as a result of charging and discharging, and such deviation has been believed to limit the usage area of batteries, which is one factor that reduces the area in which the maximum performance of the battery can be achieved. When investigating the mechanism of Li-ion deviation, however, confirming the behavior of Li-ions in the electrolyte under the same environment and conditions as when it is being used in related products was not possible using existing methods.
Toyota Motor Corp said it aims to develop a more advanced electric-car battery "in a few years" that will allow the Japanese automaker to build vehicles with up to 15 per cent greater range and battery life than they have currently.
Using techniques developed in collaboration with a Japanese publicly-financed laboratory and four universities in Japan, Toyota engineers were able to better see in "real time" how lithium ions moved inside electrodes.
Going forward, Toyota will observe the behaviour of Li-ions caused by differences in the materials and structures of cathodes, anodes, separators, and electrolytes, as well as the differences in battery control.
The company will analyse the mechanisms that cause deterioration of battery performance and will lead to R&D that can help to improve the performance and durability of batteries, to bring about longer battery life and longer driving ranges, it stated.