and transportation applications requires efficient and revolutionary electrical energy storage devices (ESDs). [2] Among the developed ESDs, rechargeable lead-acid batteries and lithium-ion batteries (LIBs) represent the most mature technologies that are widely used as power supplies in today's portable electronics, transportation, and stationary energy storage applications. [3] However, owing to the inadequate rate of improvement in energy density and cycle life, as well as cost and safety concerns of the two well-established battery technologies, there is an urgent need for energy storage technologies "beyond the lead-acid batteries and LIBs," i.e., alternative advanced battery systems to meet the rapidly growing demand of the emerging markets of electric vehicles and grid energy storage. Therefore, the search for the low cost, environmental-benignity, high energy density with rapid energy storage (high power density), and long-cycle life batteries has become one of the world's top issues. Compared with the state-of-the-art nonaqueous LIB systems, new developing aqueous rechargeable batteries, [4] especially for aqueous rechargeable multivalent metal-ion batteries (ARMMBs) by means of a multi-electron-transfer electrode reaction possess prominent advantages including cost efficiency, absolute safety, environmental benignity, and high capacity and rate capability (Figure 1a). [5] Note that the ARMMBs usually consist of a multivalent-metal anode, an aqueous electrolyte in majority and a cathode for accommodation of the multivalentmetal ions. The working mechanism in the ARMMBs is different from multivalent metal-alkaline batteries (Figure 1b, taking Zn-ion battery and Zn-alkaline battery as examples). [6] Furthermore, the high ionic conductivity of aqueous electrolytes (≈1 and 10 -3 -10 -2 S cm -1 for nonaqueous electrolytes) facilitate high-rate abilities and high-power densities of ARMMBs. [7] Therefore, owing to their better electrochemical performance and advances in the development of nanostructured materials, enormous research interests have turned to ARMMBs, leading to a huge expansion of publications/literatures in the past five years (Figure 1c). However, the insufficient energy density and limited life span of ARMMBs usually hinder their grid-scale applications in the modern society.There have been a couple of reviews published recently on the ongoing hot topic focusing on aqueous rechargeable Aqueous rechargeable multivalent metal-ion batteries (ARMMBs) have a great potential to meet the future demands in the wide spectrum of energy storage applications, ranging from wearables/portables to large-scale stationary energy storage. This is owing to the abundance of the electrode materials, their eco-friendliness, high safety, fast-charging capability, high power density, and long-cycling capability. There has been considerable progress in ARMMBs over the past ten years. However, their rather narrow operating voltage window and insufficient energy density are still the main barriers to their use as a...