University of Waterloo chemists have developed a long-lasting, safe, zinc-ion battery that costs half the price of current lithium-ion batteries. It could help communities shift from traditional power plants to renewable solar and wind energy production, where electricity storage overnight is needed.
The battery is water-based and uses cheap but safe, non-flammable, non-toxic materials, compared to expensive, flammable, organic electrolytes in lithium-ion batteries, which are used in the exploding Samsung Galaxy Note 7 smartphones reported last week and in previously reported exploding hoverboards.
Ref: A high-capacity and long-life aqueous rechargeable zinc battery using a metal oxide intercalation cathode. Nature Energy (26 August 2016) | DOI: 10.1038/nenergy.2016.119
Although non-aqueous Li-ion batteries possess significantly higher energy density than their aqueous counterparts, the latter can be more feasible for grid-scale applications when cost, safety and cycle life are taken into consideration. Moreover, aqueous Zn-ion batteries have an energy storage advantage over alkali-based batteries as they can employ Zn metal as the negative electrode, dramatically increasing energy density. However, their development is plagued by a limited choice of positive electrodes, which often show poor rate capability and inadequate cycle life. Here we report a vanadium oxide bronze pillared by interlayer Zn2+ ions and water (Zn0.25V2O5⋅nH2O), as the positive electrode for a Zn cell. A reversible Zn2+ ion (de)intercalation storage process at fast rates, with more than one Zn2+ per formula unit (a capacity up to 300 mAh g−1), is characterized. The Zn cell offers an energy density of ∼450 Wh l−1 and exhibits a capacity retention of more than 80% over 1,000 cycles, with no dendrite formation at the Zn electrode.