Development and challenges of aqueous rechargeable zinc batteries

With the rapid consumption of fossil energy resources and the increasing pollution problems, the efficient use of energy and the development of renewable energy sources is urgently needed, which demand for the large-scale electrical energy storage system with properties of high-security, low-cost, environmentally benign, remarkable capacity and long-life span. In this regard, achieving some breakthroughs in this system will have extremely important strategic impacts on future energy structure adjustments and smart grid construction. Although lithium ion battery has dominated the energy market for decades, the intrinsic drawbacks of high cost and safety issues, to a great extent, impedes its utilization in scale-up energy storage system. And recent years witnessed the significant progress of rechargeable multivalent metal ions batteries, such as Mg2+-ion, Al3+-ion, Ca2+-ion and Zn2+-ion batteries. With the unique features of high safety, low-cost, environmental friendly, abundant resources stockpile, low redox potential (–0.76 V vs. SHE), high capacity (up to 820 mAh g–1 theoretically) and energy density (5851 mAh mL−1) of metallic Zn as well as remarkable ionic conductivity of aqueous electrolyte, aqueous rechargeable zinc battery has attracted plenty of interest in recent years and exhibits great potential to be an important candidate for the next generation of high-safe and large scale energy storage system. Many researchers have paid great attention to the development of high performance aqueous rechargeable zinc battery system, including cathode materials, electrolytes and anode. And some great achievements have been obtained. Henceforth, in this review, we have systematically reviewed the research progress of aqueous rechargeable zinc battery, summarized and discussed the existing problems faced by this system and the related solutions. Based on the author’s best knowledge and understanding of aqueous rechargeable zinc battery, we have looked forward to its future research direction and made some perspectives, which is expected to pave the pathway for the understanding and further development of aqueous rechargeable zinc battery. In our view, the development of advanced solid/gel electrolyte should be attached great significance, which is a promising way to solve a series of problems existing in anode and cathode, such as cathode material dissolution, zinc anode dendrite growth, passivation and corrosion, as well as the by-products existing in the system. Moreover, the research on solid/gel electrolyte also offers some opportunities of constructing wearable and flexible electronic devices, such as smart watch, which is greatly beneficial to put forward to the practical application of aqueous rechargeable zinc battery. In addition, development of high performance cathode materials with remarkable strength of both high-voltage and high-capacity, and in-depth researches on the modification and optimization of zinc anode are the further trends of high-performance aqueous rechargeable zinc battery.