Trivalent Indium Metal as a High-Capacity, High-Efficiency, Low-Polarization, and Long-Cycling Anode for Aqueous Batteries

Abstract

Aqueous batteries using multivalent metals hold great promise for energy storage due to their low cost, high energy, and high safety. Presently, divalent metals (zinc, iron, nickel, and manganese) prevail as the leading choice, which, however, suffer from low Coulombic efficiency or dendrite growth. In stark contrast, trivalent metals have received rare attention despite their capability to unlock unique redox reactions. Herein, we investigate trivalent indium as an innovative and high-performance metal anode for aqueous batteries. The three-electron In 3+ /In redox endows a high capacity of ∼700 mAh g −1 , on par with the Zn metal. Besides, indium exhibits a suitable redox potential (−0.34 V vs standard hydrogen electrode) and dendrite-free plating process, which renders an ultrahigh Coulombic efficiency of 99.3−99.8%. More surprisingly, it features an exceedingly low polarization of 1 mV in symmetrical cells, which is 1−2 orders of magnitude lower than any reported metals. The In-MnO 2 full cell also delivers impressive performance, with a cell voltage of ∼1.2 V, a high capacity of ∼330 mAh g −1 , and a long cycling time of 680 cycles. Our work exemplifies the efficacy of exploiting trivalent metals as an excellent metal anode, which provides an exciting direction for building high-performance aqueous batteries.

Unlocking the potential of cadmium plating chemistry for low-polarization, long-cycling, and ultrahigh-efficiency aqueous metal batteries

“…Of note, such small polarization is 1-2 orders of magnitude lower than transition metals at identical conditions, 36 such as Mn (1100 mV), Fe (200 mV), Ni (300 mV), Cu (25 mV), and Zn (50 mV), as shown in Fig. 2c and Fig.…”

Copper ions-intercalated manganese dioxide self-supporting mesoporous carbon electrode for aqueous zinc-ion batteries

“…Manganese based oxides, vanadium based oxides, prussian blue analogues, and organic compounds have been extensively studied. [13][14][15][16][17] Among them, manganese oxide has attracted tremendous interest because of its high specific capacity of ~308 mAh g -1 , large operating voltage of ~1.35 V, and low toxicity. Compared with the other phases of MnO 2 (α-, β-, γ-, ε-, λ-MnO2), the layered structure of δ-MnO 2 has a large layer spacing (~0.7 nm), which makes it theoretically more suitable for Zn ion intercalation.…”