In 1991 Sony* was the first in the world to commercialize a lithium-ion rechargeable battery, forever changing the history of mobile devices.

1991 was the year Sony* lithium-ion rechargeable batteries were first used in mobile phones. By dramatically increasing the energy density from that of conventional rechargeable batteries, Sony* was able to solve issues such as the inability to use devices outdoors and the short operational life of dry cell batteries. This year, in turn, served as a turning point completely redefining the history of mobile devices.

The origin of the name for olivine-type lithium iron phosphate comes from the beautiful color of olives.

While by nature a difficult material to apply to batteries, through our original know-how we were able to harness its full potential.

Olivine-type lithium iron phosphate is a beautiful olive-colored crystal.

With a strong and solid structure, this crystal emits little oxygen and is extremely difficult to set afire.

When used in batteries, it dramatically extends the operational life but due to its low electrical conductivity, is difficult to apply as is. At Tohoku Murata we took on this challenging substance, and matching an original battery structure with our know-how for material processing, we succeeded in developing a rechargeable battery that is both safe and long-lasting. Carrying a cathode composed of this material, the rechargeable lithium-ion battery ‘fORTELION’ can last 15 years at least when charged only once a day at room temperature and is suitable for use in applications requiring a large current of energy to be released at once.

A notable feature of Tohoku Murata batteries is its gel polymer electrolytes.

By increasing the adhesiveness of cell elements, we are able to achieve numerous advantages in our batteries.

A notable feature of Tohoku Murata batteries is its gel polymer electrolytes.

Compared to conventional liquid electrolytes not only are there no leakages, but the material’s adhesiveness counteracts gases emitted by microscopic impurities within the cell itself. Its property for controlling swelling promotes reductions in size and weight and assists in increasing battery capacity and life.

This resistance to swelling also allows for a higher degree of freedom when planning and developing devices.

Our cumulative shipment of 5 billion cells is proof of the technology and reliability supporting our customers.

Since beginning production in 1991, Sony* lithium-ion rechargeable batteries have been adopted for use in devices the world over and as of April, 2015 approximately 5 billion have been shipped. This is a testament to our customer-confirmed, consistent reliability.