(450b) Rechargeable Aqueous Zinc-Ion Batteries and Supercapacitors

Rechargeable battery technologies, particularly lithium-ion batteries (LIBs) are playing a dominant role in various application including electric vehicles, portable electronics and medical tools, as highly efficient power sources. LIBs are usually regarded as clean energy technologies, since they realize the conversion between chemical energy and electric energy in a "green" manner without greenhouse gas emission. On the one hand, many transition metal elements (e.g., Ni, Co, Mn) are utilized in electrode materials, which have significant environmental impact. Moreover, a variety of chemicals (e.g., precursors for electrode materials, organic solvents for electrolyte, etc.) are consumed during battery fabrication, which makes them not "green" and exacerbates the environmental deterioration. On the other hand, the uneven distribution of lithium and relevant transition metals reserves globally leads to the high cost of LIBs, while the highly active nature of lithium and the use of volatile organic electrolyte brings huge safety issues. Both high cost and safety concerns make LIBs not only challenging in electric vehicle application as a power battery technology, but also impracticable at all for large-scale electric energy storage as storage battery technology.

In order for batteries to make real and essential contributions to sustainability, it is highly desired to develop next-generation alternative battery technologies to LIBs with much lower cost and higher reliability. Aqueous batteries and supercapacitors have garnered tremendous research interest due to high safety. Among candidates, zinc-ion based energy devices show great promise due to the high theoretical capacity of Zn metal (820 mAh g−1), proper potential (−0.76 V vs. standard hydrogen electrode), water compatibility, and high safety of Zn metal. Despite the advantages, Zn-ion based energy storage devices are faced with issues from dendritic growth and low Coulombic efficiency in the Zn anode, fast capacity decay at the cathode, and unsatisfactory performance at extreme conditions. In this talk, we utilize electrode and electrolyte engineering to develop rechargeable low-cost Zn-ion batteries and supercapacitors with excellence electrochemical performance not only suitable for large-scale energy storage but also with potential for electric vehicle applications. In addition, we also try to realize recycling and upcycling of batteries, particularly ZIBs and LIBs, to create close loop of essential materials towards circular economy. Research focus has been concentrated on the recycling of LIBs electrode (particularly cathode) by regenerating or upgrading the electrode materials. Moreover, upcycling primary batteries into rechargeable batteries has also been studied.