NGK’s Zinc Rechargeable Battery Cell Adopted for KDDI’s Base Station Trial as It Strengthens Measures Against Power Outages in Disasters
Contributing to Enhanced Resilience with a Safe and Large-Capacity Battery without Fire Risk

April 11, 2024

NGK INSULATORS, LTD. (hereinafter “NGK”) based in Nagoya, Japan, has started operating a zinc rechargeable battery that it is currently developing, after the cell was adopted in a trial for a back-up power supply for a commercial base station of KDDI CORPORATION, headquartered in Chiyoda-ku, Tokyo. The zinc rechargeable battery is being used to enhance the resilience of the base stations as an emergency storage battery. This trial is the first example in Japan of a zinc rechargeable battery being used in a base station that is in operation.

Zinc rechargeable battery cell (front) and battery module

The zinc rechargeable battery is a storage battery that uses zinc for the negative electrode and the NGK’s proprietary ceramics for the separator between the positive and negative electrodes. Since flammable organic solvent is not used for the electrolyte, the battery has a high safety profile and energy density, making it compact and giving it the characteristic of being suitable for installation in any location, including indoors.

Base stations usually contain storage batteries able to supply electric power for several hours. However, with the recent increase in severity of natural disasters, there has been an initiative to increase back-up power supply to enable continuous operation in a large-scale power outages. At the same time, there have been issues with lead storage batteries, which are the mainstream power supply for base stations, in cases such as building rooftops where they cannot be installed due to their weight.

The zinc rechargeable battery is now being trialed as a back-up power supply that can be installed anywhere as it carries no risk of internal fire or thermal runaway and has only approximately half the volume and weight of lead batteries of the same capacity, while not containing harmful lead. The introduction of the zinc rechargeable battery will enable continued operation of the base station for at least 24 hours in the event of a power outage. The zinc rechargeable battery has been installed after prior evaluation by KDDI Engineering Corporation, headquartered in Shibuya-ku, Tokyo, and plan is to verify its operation under actual conditions by using it in KDDI’s outdoor base station over the course of one year.

Going forward, NGK aims to expand the applications of the zinc rechargeable battery as a safe, large-capacity storage battery into other fields. These include infrastructure installations, such as railways, as well as public facilities such as government offices and hospitals, and commercial facilities such as shops and office buildings.

Under NGK Group Vision: Road to 2050, a mid - to long-term vision of the future of 2050, the NGK Group stated it will convert the business structure to the carbon neutral and digital society fields and aims to generate at least 100.0 billion yen in net sales in new business by the milestone year of 2030 in its New Value 1000 commitment. NGK will continue in the future to move forward on creating new products and new businesses, focusing on the development of themes that will contribute to its growth, such as the zinc rechargeable battery.

Overview of the Zinc Rechargeable Battery Used in the Trial

Installation site Isshikicho, Nishio City, Aichi Prefecture
Output 48 Volts
Capacity 1,000 ampere hours (at the beginning of lifetime)
Units installed 1
Applications Back-up power supply for base station
Start of operation April 2024

left: Housing of the zinc rechargeable battery
right: The zinc rechargeable battery

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