Zinc Ion Batteries: Structural ENgineering for Severe Environment (SENSE)

Clean energy needs to be stored in an efficient and safe configuration to help improve the environment. Li-ion batteries still dominate the electrochemical energy storage market, however, they have disadvantages of relatively high cost, potential explosion and complicated manufacture. The demands for more sustainable and safer battery technologies are constantly increasing and the utilisation of energy storage devices under severe environments are required to satisfy practical applications. Aqueous battery systems have remarkable potential as next-generation energy storage devices because the cost of raw materials can be reduced, the battery can be fabricated in a more sustainable and facile process and explosive accidents can be avoided. Zn-ion batteries in aqueous/hydrogel electrolyte are favourable candidates due to their relatively low cost and safety advantages. Importantly, Zn-ion batteries can be a ready-to-use technique for all battery companies as they can use the same battery fabrication facilities as Li-ion batteries. However, the specific capacity, energy and power density of current Zn-ion batteries are restricted due to the relatively large hydrated zinc ions and high polarization of bivalent zinc ions. Therefore, the development on the cathodes of Zn-ion batteries have been motivated. Manganese oxide-based materials are favourable due to their suitable structures, abundant and cost-effective properties, environmentally friendly nature and a large working voltage window. But the problems such as limited intercalated channels, poor stability during battery charge/discharge processes, unclarified and complicated mechanism and low electron conductivity of manganese oxide-based cathodes need to be solved, thus the innovation of structures for manganese oxide-based cathodes calls for further exploration. In the SENSE project, manganese-based cathode materials coupled with suitable hydrogel electrolytes for Zn-ion batteries will be designed via multi-level structural engineering to utilise them under harsh conditions, for the purpose of innovating inexpensive and high-performance devices. Through collaborations with both academic and industrial partners, state-of-the-art materials and device characterisation techniques will be used to understand the underlying mechanisms for battery behaviours.

After successfully fulfilling SENSE, Zn-ion batteries can exhibit a volumetric energy density of > 650 Wh L-1 and a power density of > 220 W L-1. The energy price of which can be estimated as £50/kWh, lower than that of Li-ion batteries (£126/kWh), and Ni-Fe batteries (£58/kWh). Therefore, SENSE will not only help advance the quality of battery research and innovative efforts in the UK, but also strengthen and stimulate the development of new technologies in the UK battery industry.