Fujitsu-backed FDK Claims Nickel Zinc Batteries Ready For Use In UPSes

Japanese battery maker FDK reckons a major improvement in its Ni-Zn battery has proven its durability enough to deem it practical for use as an Uninterruptible Power Supply (UPS).

The batteries, having made their debut in March, have undergone long-term testing to allegedly prove it maintains 70 percent capacity after 800 charge and discharge cycles – double the standard life of lead-acid batteries, claimed FDK.

The batteries were also run through a test that saw them neglected in an outdoor cabinet in temperatures fluctuating between 0℃ in winter and 50℃ in summer. FDK said the test batteries continued to operate safely while preserving their initial capacity.

In addition to a longer life cycle and enduring large temperature fluctuations, the Fujitsu-backed company said the Ni-Zn batteries were lighter with lower environmental impact than the lead-acid alternatives traditionally used in UPSes. However, we're told they charge similarly.

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The battery-maker feels so confident in the product, it pledged to upgrade facilities, expand sample shipments to customers, and consider mass production.

Like other Ni-Zn batteries, FDK’s ZR-4/3FAUP, is essentially a hydride battery that has had its negative electrode material replaced with a zinc compound, a change that creates a chemistry distinct to Ni-Zn batteries. These types of batteries combine a nickel-metal hydride cathode with the zinc negative electrode found in alkaline batteries.

In the past, poor cycle life has hindered Ni-Zn use. The zinc tends to migrate and cause pesky dendritic growth, an inconvenience as it can produce a short. But recent developments in energy storage technology – like the use of additives in the anode and electrolyte, and improvements in separator design - have made this less of an issue in modern Ni-Zn batteries.

What Ni-Zn batteries do excel at is power density – a quality they have twice as much of when compared to lead-acid batteries. This means they can provide the rapid charge required for items like a UPS in a datacenter and other situations where the need for quick charge outweighs concerns of device longevity.

“The Ni-Zn battery is among the most promising ones for stationary applications. They use water based electrolytes (alkaline battery) and they are cost effective compared to lithium-ion batteries - and of course much better than lead acid batteries in terms of energy density,” Dr Richard Yazami, inventor of the graphite anode told The Register.

“The Ni-Zn battery may find a niche market especially in the back up and energy storage systems. However, their use in EV is still uncertain,” Yazami added.

The energy density of Ni-Zn is not near that of lithium-ion batteries, meaning they won’t likely be the battery of choice for electric vehicles anytime soon.

While FDK has said the battery could replace power supplies, the company hasn’t mentioned use in servers, but more resilient options are seldom unwelcome. ®