Aqueous zinc-ion batteries have been regarded as a promising alternative to large-scale energy storage, due to associated low-cost, improved safety and environmental friendliness. However, a high-performance cathode m...Aqueous zinc-ion batteries have been regarded as a promising alternative to large-scale energy storage, due to associated low-cost, improved safety and environmental friendliness. However, a high-performance cathode material for both rate capability and specific capacity is still a challenge. One kind of the more promising candidates are sodium manganese oxide(NMO) materials, although they suffer from individual issues and need to be further improved. Herein, we present a novel mixed phase NMO material composed of nearly equal amounts of Na(0.55)Mn2O4 and Na(0.7)MnO(2.05). The structured configuration with particle size of 200–500 nm is found to be beneficial towards improving the ion diffusion rate during the charge/discharge process. Compared with Na(0.7)MnO(2.05) and Na(0.55)Mn2O4, the mixed phase NMO demonstrates an enhanced rate capability and excellent long-term cycling stability with a capacity retention of 83% after 800 cycles. More importantly, the system also delivers an impressive energy density and power density, as 378 W·h·kg^-1 at 68.7 W·kg^-1, or 172 W·h·kg^-1 at 1705 W·kg^-1. The superior electrochemical performance is ascribed to the fast Zn^2+ diffusion rate because of a large ratio of capacitive contribution(63.9% at 0.9 m V·s^-1). Thus, the mixed phase route provides a novel strategy to enhance electrochemical performance, enabling mixed phase NMO as very promising material towards large-scale energy-storage applications.展开更多
Vanadium oxides as cathode for zinc-ion batteries have attracted much attention because of their high theoretical capacity,flexible layered structure and abundant resources.However,cathodes are susceptible to the coll...Vanadium oxides as cathode for zinc-ion batteries have attracted much attention because of their high theoretical capacity,flexible layered structure and abundant resources.However,cathodes are susceptible to the collapse of their layered structure and the dissolution of vanadium after repeated long cycles,which worsen their capacities and cycling stabilities.Herein,a synergistic engineering of calcium-ion intercalation and polyaniline coating was developed to achieve the superior electrochemical performance of vanadium pentoxide for zinc-ion batteries.The pre-intercalation of calcium-ion between vanadium pentoxide layers as pillars increase the crystal structure’s stability,while the polyaniline coating on the cathodes improves the conductivity and inhibits the dissolution of vanadium.This synergistic engineering enables that the battery system based-on the polyaniline coated calcium vanadate cathode to deliver a high capacity of 406.4 mAh·g^(−1)at 1 A·g^(−1),an ultralong cycle life over 6000 cycles at 10 A·g^(−1)with 93%capacity retention and high-rate capability.The vanadium oxide cathode with synergistic engineering of calcium-ion intercalation and polyaniline coating was verified to effectively improve the electrochemical performance of zinc-ion batteries.展开更多
基金the financial support from the China Scholarship Council(CSC)supported by the National Natural Science Foundation of China(21905037)the Fundamental Research Funds for the Central Universities(3132019328,3132020151)。
文摘Aqueous zinc-ion batteries have been regarded as a promising alternative to large-scale energy storage, due to associated low-cost, improved safety and environmental friendliness. However, a high-performance cathode material for both rate capability and specific capacity is still a challenge. One kind of the more promising candidates are sodium manganese oxide(NMO) materials, although they suffer from individual issues and need to be further improved. Herein, we present a novel mixed phase NMO material composed of nearly equal amounts of Na(0.55)Mn2O4 and Na(0.7)MnO(2.05). The structured configuration with particle size of 200–500 nm is found to be beneficial towards improving the ion diffusion rate during the charge/discharge process. Compared with Na(0.7)MnO(2.05) and Na(0.55)Mn2O4, the mixed phase NMO demonstrates an enhanced rate capability and excellent long-term cycling stability with a capacity retention of 83% after 800 cycles. More importantly, the system also delivers an impressive energy density and power density, as 378 W·h·kg^-1 at 68.7 W·kg^-1, or 172 W·h·kg^-1 at 1705 W·kg^-1. The superior electrochemical performance is ascribed to the fast Zn^2+ diffusion rate because of a large ratio of capacitive contribution(63.9% at 0.9 m V·s^-1). Thus, the mixed phase route provides a novel strategy to enhance electrochemical performance, enabling mixed phase NMO as very promising material towards large-scale energy-storage applications.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.22101309,52103277 and U1804126)the Key Scientific and Technological Project of Henan Province(Grant No.222102240001)the Startup Research of Henan Academy of Sciences(Grant No.231817001).
文摘Vanadium oxides as cathode for zinc-ion batteries have attracted much attention because of their high theoretical capacity,flexible layered structure and abundant resources.However,cathodes are susceptible to the collapse of their layered structure and the dissolution of vanadium after repeated long cycles,which worsen their capacities and cycling stabilities.Herein,a synergistic engineering of calcium-ion intercalation and polyaniline coating was developed to achieve the superior electrochemical performance of vanadium pentoxide for zinc-ion batteries.The pre-intercalation of calcium-ion between vanadium pentoxide layers as pillars increase the crystal structure’s stability,while the polyaniline coating on the cathodes improves the conductivity and inhibits the dissolution of vanadium.This synergistic engineering enables that the battery system based-on the polyaniline coated calcium vanadate cathode to deliver a high capacity of 406.4 mAh·g^(−1)at 1 A·g^(−1),an ultralong cycle life over 6000 cycles at 10 A·g^(−1)with 93%capacity retention and high-rate capability.The vanadium oxide cathode with synergistic engineering of calcium-ion intercalation and polyaniline coating was verified to effectively improve the electrochemical performance of zinc-ion batteries.
