Researchers from Stanford University and Toyota have developed a novel battery design for grid-scale energy storage. The battery has electrodes made of zinc and nickel, inexpensive metals that are available commercially. Few zinc batteries are reliably rechargeable, however.

Tiny fibres called dendrites that form on the zinc electrode during charging can eventually reach the nickel electrode, causing the battery to short circuit and fail. Researchers solved the dendrite problem by redesigning the battery.

Instead of having the zinc and nickel electrodes face one another, as in a conventional battery, the researchers separated them with a plastic insulator and wrapped a carbon insulator around the edges of the zinc electrode.

“With our design, zinc ions are reduced and deposited on the exposed back surface of the zinc electrode during charging,” Shougo Higashi, a visiting scientist from Toyota Central R&D Labs Inc. and lead author of the study, said in a release. “Therefore, even if zinc dendrites form, they will grow away from the nickel electrode and will not short the battery.”

EDNA zinc battery 01 Figure 1: A conventional zinc (Zn) battery (left) short circuits when dendrites growing from the zinc anode make contact with the metal cathode. The redesigned battery (right) uses plastic and carbon insulators to prevent zinc dendrites from reaching the cathode. (Source: Shougo Higashi/Stanford)

The team charged and discharged the battery more than 800 times without shorting, the release stated.

Yi Cui, associate professor of materials science and engineering at Stanford, said the simple design could be applied to a wide range of metal batteries. The technology would also be advantageous for solar and wind farms—or anywhere that requires great energy storage.

“Solar and wind farms should be able to provide around-the-clock energy for the electric grid, even when there’s no sunlight or wind,” Cui said in the release. “That will require inexpensive batteries and other low-cost technologies big enough to store surplus clean energy for use on demand.”

EDNA zinc battery 02 Figure 2: A dendrite. (Source: Nature Communications/Stanford)

Findings were published Nature Communications. Other co-authors are Seok Woo Lee and Jang Soo Lee of Stanford, and Kensuke Takechi of Toyota Central R&D Labs Inc.