Search

Aqueous zinc (Zn) battery with remarkable advantages of high safety, low cost, and high reversibility is highly applauded in next‐generation low‐speed electric vehicles and large‐scale energy storage applications. However, Zn anode suffers from a series of unfavorable reactions, hindering its progress toward industrialization. Herein, a functionalized hydrogel film is designed using polydopamine and polyacrylamide crosslinking (PDAM) as the Zn protective layer to stabilize the Zn anode. Benefiting from the strong interaction of Zn2+ with PDAM, the primary solvation shell of Zn2+ is regulated by PDAM into the form of PDAM–Zn2+‐5H2O. This remodeling prevents Zn dendrite growth and inhibits water‐induced side reactions. As a result, the Zn–MnO2 battery using PDAM‐coated Zn anode exhibits excellent cycling stability, demonstrating over 1150 cycles at an areal capacity of 5 mAh cm−2 with an average Coulombic efficiency (CE) of 96.5%. For a scaled‐up PDAM@Zn–MnO2 pouch cell with a capacity of 80 mAh, stable cycling of over 200 cycles with an average CE of 91.9% is achieved. The superior Zn–MnO2 battery enabled by the functionalized hydrogel protective film enlightens an arena toward next‐generation energy storage applications. [ABSTRACT FROM AUTHOR]

Aqueous zinc–chlorine battery with high discharge voltage and attractive theoretical energy density is expected to become an important technology for large‐scale energy storage. However, the practical application of Zn–Cl2 batteries has been restricted due to the Cl2 cathode with sluggish kinetics and low Coulombic efficiency (CE). Here, an aqueous Zn–Cl2 battery using an inexpensive and effective MnO2 redox adsorbent (referred to Zn‐Cl2@MnO2 battery) to modulate the electrochemical performance of the Cl2 cathode is developed. Density functional theory calculations reveal that the existence of the intermediate state Clads free radical catalyzed by MnO2 on the Cl2 cathode contributes to the charge storage capacity, which is the key to modulate the electrode and improve the electrochemical performance. Further analysis of the Cl2 cathode kinetics discloses the adsorption and catalytic roles of the MnO2 redox adsorbent. The Zn–Cl2@MnO2 battery displays an enhanced discharge voltage of 2.0 V at a current density of 2.5 mA cm−2, and stable 1000 cycles with an average CE of 91.6%, much superior to the conventional Zn–Cl2 battery with an average CE of only 66.8%. The regulation strategy to the Cl2 cathode provides opportunities for the future development of aqueous Zn‐Cl2 batteries. [ABSTRACT FROM AUTHOR]

Structural batteries are attractive for weight reduction in vehicles, such as cars and airplanes, which requires batteries to have both excellent mechanical properties and electrochemical performance. This work develops a scalable and feasible tree‐root‐like lamination at the electrode/separator interface, which effectively transfers load between different layers of battery components and thus dramatically enhances the flexural modulus of pouch cells from 0.28 to 3.1 GPa. The underlying mechanism is also analyzed by finite element simulations. Meanwhile, the interfacial lamination has a limited effect on the electrochemical performance of Li‐ion cells. A graphite/LiNi0.5Mn0.3Co0.2O2 full cell with such interfacial lamination delivers a steady discharge capacity of 148.6 mAh g−1 at C/2 and 95.5% retention after 500 cycles. Moreover, the specific energy only decreases by 3%, which is the smallest reduction reported so far in structural batteries. A prototype of "electric wings" is also demonstrated, which allows an aircraft model to fly steadily. This work illustrates that engineering interfacial adhesion is an effective and scalable approach to develop structural batteries with excellent mechanical and electrochemical properties. [ABSTRACT FROM AUTHOR]

Aqueous rechargeable hydrogen gas batteries have low cost and high safety, which are expected to be used in large-scale energy storage. Here, we design a novel static vanadium-hydrogen gas (V-H) battery by pairing V3+/VO 2 + liquid redox cathode with the hydrogen gas anode. The two-electron reactions between V3+ and VO 2 + in static hydrogen gas batteries is reported for the first time. The V-H battery has a volumetric capacity of 18.1 Ah/L and an energy efficiency of 61 % at a high current density of 500 mA/cm2. Moreover, it achieves a high capacity retention of 80 % after 900 cycles and an energy density of 22.6 Wh/L at 300 mA/cm2. Finite element simulation proves excellent reversibility of the anode HER/HOR reactions and cathode V3+/VO 2 + redox reactions. This study sheds light on the development of cost-effective, high-energy density, long cycle life, liquid-phase cathode hydrogen batteries for large-scale energy storage applications. [Display omitted] [ABSTRACT FROM AUTHOR]