Safer alternative to Li-ion batteries claimed

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Researchers at the US Naval Research Laboratory’s (NRL) Chemistry Division say they have developed a safer alternative to lithium-ion batteries. In their work, the team has demonstrated a breakthrough in nickel-zinc (Ni-Zn) technology, where a 3D zinc ‘sponge’ is used to replace the traditional powdered zinc anode. The result is said to be a water based battery with an energy content and rechargeability that rivals lithium-ion batteries.

“Our team at the NRL pioneered the architectural approach to the redesign of electrodes for next-generation energy storage,” said Dr Debra Rolison, senior scientist and principal investigator. “The 3D sponge form factor allows us to reimagine zinc for the 21st Century.”

While zinc-based batteries are dominant in single-use applications, they are not considered rechargeable in practice due to their tendency to grow dendrites inside the battery.

“The key to realising rechargeable Zn based batteries lies in controlling the behaviour of the zinc during cycling,” said researcher Joseph Parker. “Electric currents are more uniformly distributed within the sponge, making it physically difficult to form dendrites.”

The NRL team has demonstrated Ni-3D Zn performance in three ways: extending lifetime in single-use cells; cycling cells more than 100 times at an energy content competitive with lithium-ion batteries; and cycling cells more than 50,000 times in short duty-cycles with intermittent power bursts, similar to the way in which batteries are used in some hybrid vehicles.

“We can now offer an energy-relevant alternative, from drop-in replacements for lithium-ion to new opportunities in portable and wearable power, and manned and unmanned electric vehicles," said Dr Jeffery Long, “while reducing safety hazards, easing transportation restrictions, and using earth-abundant materials.”