There is an urgent need for low-cost,high-energy-density,environmentally friendly energy storage devices to fulfill the rapidly increasing need for electrical energy storage.Multi-electron redox is considerably crucia...There is an urgent need for low-cost,high-energy-density,environmentally friendly energy storage devices to fulfill the rapidly increasing need for electrical energy storage.Multi-electron redox is considerably crucial for the development of high-energy-density cathodes.Here we present highperformance aqueous zinc-manganese batteries with reversible Mn2+/Mn4+ double redox.The active Mn4+is generated in situ from the Mn2+-containing MnOx nanoparticles and electrolyte.Benefitting from the low crystallinity of the birnessite-type MnO2 as well as the electrolyte with Mn2+additive,the MnOX cathode achieves an ultrahigh energy density with a peak of845.1 Wh kg-1 and an ultralong lifespan of 1500 cycles.The combination of electrochemical measurements and material characterization reveals the reversible Mn2+/Mn4+double redox(birnessite-type MnO2? monoclinic MnOOH and spinel ZnMn2O4 H?Mn2+ions).The reversible Mn2+/Mn4+double redox electrode reaction mechanism offers new opportunities for the design of low-cost,high-energy-density cathodes for advanced rechargeable aqueous batteries.展开更多
In order to optimize and select the appropriate binder to improve the electrochemical performance of aqueous zinc-manganese batteries,the influences of water-soluble binders and oil-based binders on the zinc storage p...In order to optimize and select the appropriate binder to improve the electrochemical performance of aqueous zinc-manganese batteries,the influences of water-soluble binders and oil-based binders on the zinc storage performance of manganese-based cathode materials were systematically investigated.The results show that the water-soluble binders with large numbers of hydroxyl and carboxyl groups are easily soluble in aqueous electrolytes,leading to poor electrochemical performance.Fortunately,the cathodes with polyvinylidene fluoride-hexafluoropropylene(PVDF-HFP)binder display high specific capacity of 264.9 mA·h/g and good capacity retention of 92%after 90 cycles at 100 mA/g.Meanwhile,PVDF-HFP binder with plenty of hydrophobic groups presents excellent ability in inhibiting cracks on the surface of electrode,reducing voltage polarization and charge transfer resistance,as well as maintaining electrode integrity.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51772331)the National Key Technologies R&D Program(Grant No.2018YFB1106000).
文摘There is an urgent need for low-cost,high-energy-density,environmentally friendly energy storage devices to fulfill the rapidly increasing need for electrical energy storage.Multi-electron redox is considerably crucial for the development of high-energy-density cathodes.Here we present highperformance aqueous zinc-manganese batteries with reversible Mn2+/Mn4+ double redox.The active Mn4+is generated in situ from the Mn2+-containing MnOx nanoparticles and electrolyte.Benefitting from the low crystallinity of the birnessite-type MnO2 as well as the electrolyte with Mn2+additive,the MnOX cathode achieves an ultrahigh energy density with a peak of845.1 Wh kg-1 and an ultralong lifespan of 1500 cycles.The combination of electrochemical measurements and material characterization reveals the reversible Mn2+/Mn4+double redox(birnessite-type MnO2? monoclinic MnOOH and spinel ZnMn2O4 H?Mn2+ions).The reversible Mn2+/Mn4+double redox electrode reaction mechanism offers new opportunities for the design of low-cost,high-energy-density cathodes for advanced rechargeable aqueous batteries.
基金supported by the National Natural Science Foundation of China (Nos.51932011, 51972346)the Hunan Natural Science Fund for Distinguished Young Scholar, China (No. 2021JJ10064)+1 种基金the Program of Youth Talent Support for Hunan Province, China (No. 2020RC3011)the Innovation-Driven Project of Central South University, China (No. 2020CX024)
文摘In order to optimize and select the appropriate binder to improve the electrochemical performance of aqueous zinc-manganese batteries,the influences of water-soluble binders and oil-based binders on the zinc storage performance of manganese-based cathode materials were systematically investigated.The results show that the water-soluble binders with large numbers of hydroxyl and carboxyl groups are easily soluble in aqueous electrolytes,leading to poor electrochemical performance.Fortunately,the cathodes with polyvinylidene fluoride-hexafluoropropylene(PVDF-HFP)binder display high specific capacity of 264.9 mA·h/g and good capacity retention of 92%after 90 cycles at 100 mA/g.Meanwhile,PVDF-HFP binder with plenty of hydrophobic groups presents excellent ability in inhibiting cracks on the surface of electrode,reducing voltage polarization and charge transfer resistance,as well as maintaining electrode integrity.
