Looking beyond lithium-ion technology – Aqueous NaOH battery

Highlights: ► A novel sodium aqueous rechargeable battery is developed. ► Intercalation of sodium in aqueous NaOH electrolyte is achieved. ► Sodium battery delivered higher energy density of 300 Wh/kg. ► It has a potential interest for smart grid applications. - Abstract: The objective of this work is to investigate a water based sodium battery technology. The new concept proposed here for an aqueous rechargeable battery is replacing lithium hydroxide with a sodium hydroxide electrolyte in the patented technology developed at Murdoch University. Alternative energy storage system using abundantly available sodium as the aqueous electrolyte coupled with Zn anode and environmentally friendly MnO2 cathode are investigated and found feasible. Sodium intercalation and de-intercalation mechanism is identified in MnO2|NaOH|Zn cell yielding 225 against 142 mAh/g for LiOH counterpart. The preliminary studies of the aqueous NaOH battery showed improved energy density and voltaic efficiency.