Hitachi aims for 10-year lithium-ion battery life

Hitachi has created a prototype of a rechargeable lithium-ion battery cell with tweaks that promise to double the working life of the battery to more than 10 years.

Lithium-ion (Li-ion) batteries are found in consumer electronics such as mobile phones and laptops, but Hitachi said the new technology will be aimed first at industrial batteries for electric vehicles and wind farms.

Although Li-ion batteries have around four times the power density as lead-acid cells, their relatively high cost and less than five-year service life has made them unattractive for larger tasks and fixed installations where lead-acid batteries can go 10 years before replacement.

The company said on Monday it had developed a new composite oxide material — a lithium-manganese spinel (LiMn₂0₄) — for the battery's cathode, which improves its resistance to attack by acids in the electrolyte, a major lifetime determinant. It also reduced the build up of crystal deposits within the electrolyte, something that also shortens a battery's life.

Although the company has not provided full details of these changes, it has said that the cathode is mostly composed of manganese instead of the more commonly used cobalt: manganese is far more easily obtainable but so far has not been suitable for this battery chemistry.

The battery was prototyped with Shin-Kobe Electric Machinery Co Ltd and was produced in association with the Japanese government's New Energy and Industrial Technology Development Organisation, set up to spur power research. Hitachi did not specify when the battery would enter production.

Hitachi, which reported its fourth annual loss for the financial year ended 31 March, has said it will concentrate on ecological businesses including batteries for electric vehicles as part of its plan to return to profitability.

Last year, researchers at the Graz University of Technology in Austria said they had developed a silicon gel that could make Li-ion batteries 10 times more efficient.