Cathode active materials for lithium-ion batteries can be produced at low temperatures

Newswise – Layered Lithium Cobalt Oxide, the main component of lithium-ion batteries, is synthesized at 300°C and with a short lifetime of 30 minutes.

Lithium ion batteries (LIB) are the most commonly used battery type in consumer electronics and electric vehicles. Lithium cobalt oxide (LiCoO2) is a compound used for the cathode in LIBs for handheld electronics. Traditionally, the synthesis of this compound requires temperatures in excess of 800°C and takes 10 to 20 hours to complete.

A team of researchers from Hokkaido University and Kobe University, led by Professor Masaki Matsui at Hokkaido University's Faculty of Science, has developed a new method for synthesizing lithium cobalt oxide at temperatures up to 300°C and a duration of up to 30 minutes. Their findings were published in the journal Inorganic chemistry.

“Lithium cobalt oxide can typically be synthesized in two forms,” ​​Matsui explains. “One form is a layered rock salt structure, called the high-temperature phase, and the other form is a spinel framework structure, called the low-temperature phase. layered LiCoO2 Used in Li-ion batteries.

Using cobalt hydroxide and lithium hydroxide as starting materials and sodium or potassium hydroxide as additives, the group conducted a series of high-precision experiments to synthesize layered LiCoO under different conditions.2 crystals. The process was called the “hydroflux process”. They were also able to identify the reaction pathway that led to the formation of the layered crystals.

“By understanding the reaction pathway, we were able to identify the factors that facilitated the crystal growth of layered LiCoO.2” said Matsui. “Specifically, the presence of water molecules in the starting materials significantly improves the crystallinity of the final product.”

The team also measured the electrochemical properties of layered LiCoO2showing that they were only marginally inferior to commercially available LiCoO2 Synthesized by traditional high temperature method.

“This work is the first experimental demonstration of the thermochemical stability of layered LiCoO2 At low temperatures under atmospheric pressure,” concludes Matsui. “Our development of this hydroflux process will enable energy-saving measures in various ceramic manufacturing processes. Our immediate next steps will be to improve the hydroflux process based on our understanding of the reaction pathway. “