Low cost battery has potential as grid storage solution

Prof Linda Nazar and her colleagues from the Faculty of Science at the University of Waterloo developed the long-lasting zinc-ion battery, which costs half the price of current lithium-ion batteries. Their findings are published in Nature Energy.

The battery is said to use safe, non-flammable, non-toxic materials and a pH-neutral water-based salt. It consists of a water-based electrolyte, a pillared vanadium oxide positive electrode, and an inexpensive metallic zinc negative electrode.

The battery generates electricity through intercalation, where positively charged zinc ions are oxidised from the zinc metal negative electrode, travel through the electrolyte and insert between the layers of vanadium oxide nanosheets in the positive electrode. This drives the flow of electrons in the external circuit, creating an electrical current. The reverse process occurs on charge.

The cell is claimed to represent the first demonstration of zinc ion intercalation in a solid-state material that satisfies four vital criteria: high reversibility, rate and capacity, and no zinc dendrite formation. According to the University, it provides over 1,000 cycles with 80 per cent capacity retention and an estimated energy density of 450 watt-hours per litre. Lithium-ion batteries also operate by intercalation - of lithium ions - but they typically use expensive, flammable, organic electrolytes.