Zinc-lignin batteries show promise for cheap storage

Lignin – a waste product from the paper industry – and zinc – an abundant metal – are both recyclable and cheap. While zinc is already widely used in disposable batteries, its use in rechargeable batteries has been hampered by durability issues, as it reacts with water in electrolyte solutions to produce hydrogen gas and dendritic growth.

To overcome this, the researchers used a potassium polyacrylate-based water-in-polymer salt electrolyte (WiPSE), which stabilises the zinc. The Swedish team, which included members from Linköping, Karlstad and Chalmers universities, demonstrated that a zinc-lignin battery with WiPSE could be cycled more than 8,000 times, while still retaining 80 per cent of its performance. The work is published in Energy & Environmental Materials.

“Our sustainable battery offers a promising alternative where energy density is not critical,” said Ziyauddin Khan, a researcher at the Laboratory of Organic Electronics at Linköping University.

“While lithium-ion batteries are useful when handled correctly, they can be explosive, challenging to recycle, and problematic in terms of environmental and human rights issues when specific elements like cobalt are extracted.