Aqueous Zn-ion battery(AZIB)has become an attractive technology because of its unique features of low cost,high safety and the eco-friendliness.MnO_(2) is the model cathode material for AZIB since the first report on ...Aqueous Zn-ion battery(AZIB)has become an attractive technology because of its unique features of low cost,high safety and the eco-friendliness.MnO_(2) is the model cathode material for AZIB since the first report on reversible Zn-MnO_(2) battery,but recent studies have unveiled different charge storage mechanisms.Due to revamping of the electrochemistry and redesigning of the electrolyte and interface,there is tremendous performance enhancement in AZIB.This mini Review will first give a brief introduction of ZIB,including fundamentals of materials and components,and the progress in recent years.Then,a general classification of working mechanisms related to MnO_(2) in neutral and mildly acidic electrolyte is elaborated.Our focus is put on the recent blossoming Zn-MnO_(2) electrolytic mechanism,which has given birth to the Zn-MnO_(2) redox flow batteries that are highly promising for large-scale static energy storage.展开更多
Stretchable electronics are in high demand for next-generation wearable devices, but their fabrication is still challenging. Stretchable conductors, flexible pressure sensors, and foldable light-emitting diodes （LEDs...Stretchable electronics are in high demand for next-generation wearable devices, but their fabrication is still challenging. Stretchable conductors, flexible pressure sensors, and foldable light-emitting diodes （LEDs） have been reported; however, the fabrication of stable stretchable batteries, as power suppliers for wearable devices, is significantly behind the development of other stretchable electronics. Several stretchable lithium-ion batteries and primary batteries have been fabricated, but their low capacities and complicated manufacturing processes are obstacles for practical applications. Herein, we report a stretchable zinc/manganese-oxide （Zn-MnO2） full battery based on a silver-nanowire- coated sponge prepared via a facile dip-coating process. The spongy electrode, with a three-dimensional （3D） binary network structure, provided not only high conductivity and stretchability, but also enabled a high mass loading of electrochemically active materials （Zn and MnO2 particles）. The fabricated Zn-MnO2 battery exhibited an areal capacity as high as 3.6 mAh·cm^-2 and could accommodate tensile strains of up to 100% while retaining 89% of its original capacity. The facile solution-based strategy of dip-coating active materials onto a cheap sponge-based stretchable current collector opens up a new avenue for fabricating stretchable batteries.展开更多
A two-dimensional mathematical model based on the macrohomogeneous theory of porous electrodes was developed for a cylindrical Zn-MnO2 alkaline cell. The model was applied to understand the effect of the length of the...A two-dimensional mathematical model based on the macrohomogeneous theory of porous electrodes was developed for a cylindrical Zn-MnO2 alkaline cell. The model was applied to understand the effect of the length of the anode current collector on the cell performance. Results are presented for the continuous discharge at a high rate of 1A and a moderate rate of 0.2A for a AA-sized cell. With a typical length of an anode current collector at about 70%of the cell height, the analysis showed that an increase in the length of the anode current collector would benefit the lower rate of discharge more than the higher rate of discharge.展开更多
To improve the performance of Ni-Zn ferrites for power field use,the influence of MnO2 additive on the properties of Ni-Zn ferrites was investigated by the conventional powder metallurgy.The results show that MnO2 doe...To improve the performance of Ni-Zn ferrites for power field use,the influence of MnO2 additive on the properties of Ni-Zn ferrites was investigated by the conventional powder metallurgy.The results show that MnO2 does not form a visible second phase in the doping mass fraction range of（0-2.0%）.The average grain size,sintering density and real permeability gradually decrease with the increase of the MnO2 content.And the DC resistivity continuously increases with the increase of MnO2 content.The saturation magnetization（magnetic moment in unit mass） first increases slightly when mass fraction of MnO2 is less than 0.4% MnO2,and then gradually decreases with increasing the MnO2 mass fraction due to the exchange interaction of the cations.When the excitation frequency is less than 1 MHz,the power loss（Pcv） continuously increases with increasing the MnO2 content due to the decrease of average grain size.However,when the excitation frequency exceeds 1 MHz,eddy current loss gradually becomes the predominant contribution to Pcv.And the sample with a higher resistivity favors a lower Pcv,except for the sample with 2.0% MnO2.The sample without additive has the best Pcv when worked at frequencies less than 1 MHz;and the sample with 1.6% MnO2 additive has the best Pcv when worked at frequencies higher than 1 MHz.展开更多
基金supported by West Light Foundation of The Chinese Academy of Sciences(XAB2019AW09)Singapore Ministry of Education Tier 1 grants(RG 10/18,RG 157/19)。
文摘Aqueous Zn-ion battery(AZIB)has become an attractive technology because of its unique features of low cost,high safety and the eco-friendliness.MnO_(2) is the model cathode material for AZIB since the first report on reversible Zn-MnO_(2) battery,but recent studies have unveiled different charge storage mechanisms.Due to revamping of the electrochemistry and redesigning of the electrolyte and interface,there is tremendous performance enhancement in AZIB.This mini Review will first give a brief introduction of ZIB,including fundamentals of materials and components,and the progress in recent years.Then,a general classification of working mechanisms related to MnO_(2) in neutral and mildly acidic electrolyte is elaborated.Our focus is put on the recent blossoming Zn-MnO_(2) electrolytic mechanism,which has given birth to the Zn-MnO_(2) redox flow batteries that are highly promising for large-scale static energy storage.
基金We acknowledge the funding support from the National Natural Science Foundation of China （Nos. 21431006 and 21761132008）, the Foundation for Innovative Research Groups of the National Natural Science Foundation of China （No. 21521001）, Key Research Program of Frontier Sciences, CAS （No. QYZDJ-SSW- SLH036）, the National Basic Research Program of China （No. 2014CB931800）, and the Users with Excellence and Scientific Research Grant of Hefei Science Center of CAS （No. 2015HSC-UE007）.
文摘Stretchable electronics are in high demand for next-generation wearable devices, but their fabrication is still challenging. Stretchable conductors, flexible pressure sensors, and foldable light-emitting diodes （LEDs） have been reported; however, the fabrication of stable stretchable batteries, as power suppliers for wearable devices, is significantly behind the development of other stretchable electronics. Several stretchable lithium-ion batteries and primary batteries have been fabricated, but their low capacities and complicated manufacturing processes are obstacles for practical applications. Herein, we report a stretchable zinc/manganese-oxide （Zn-MnO2） full battery based on a silver-nanowire- coated sponge prepared via a facile dip-coating process. The spongy electrode, with a three-dimensional （3D） binary network structure, provided not only high conductivity and stretchability, but also enabled a high mass loading of electrochemically active materials （Zn and MnO2 particles）. The fabricated Zn-MnO2 battery exhibited an areal capacity as high as 3.6 mAh·cm^-2 and could accommodate tensile strains of up to 100% while retaining 89% of its original capacity. The facile solution-based strategy of dip-coating active materials onto a cheap sponge-based stretchable current collector opens up a new avenue for fabricating stretchable batteries.
文摘A two-dimensional mathematical model based on the macrohomogeneous theory of porous electrodes was developed for a cylindrical Zn-MnO2 alkaline cell. The model was applied to understand the effect of the length of the anode current collector on the cell performance. Results are presented for the continuous discharge at a high rate of 1A and a moderate rate of 0.2A for a AA-sized cell. With a typical length of an anode current collector at about 70%of the cell height, the analysis showed that an increase in the length of the anode current collector would benefit the lower rate of discharge more than the higher rate of discharge.
基金Projects(50702011,60721001)supported by the National Natural Science Foundation of China
文摘To improve the performance of Ni-Zn ferrites for power field use,the influence of MnO2 additive on the properties of Ni-Zn ferrites was investigated by the conventional powder metallurgy.The results show that MnO2 does not form a visible second phase in the doping mass fraction range of（0-2.0%）.The average grain size,sintering density and real permeability gradually decrease with the increase of the MnO2 content.And the DC resistivity continuously increases with the increase of MnO2 content.The saturation magnetization（magnetic moment in unit mass） first increases slightly when mass fraction of MnO2 is less than 0.4% MnO2,and then gradually decreases with increasing the MnO2 mass fraction due to the exchange interaction of the cations.When the excitation frequency is less than 1 MHz,the power loss（Pcv） continuously increases with increasing the MnO2 content due to the decrease of average grain size.However,when the excitation frequency exceeds 1 MHz,eddy current loss gradually becomes the predominant contribution to Pcv.And the sample with a higher resistivity favors a lower Pcv,except for the sample with 2.0% MnO2.The sample without additive has the best Pcv when worked at frequencies less than 1 MHz;and the sample with 1.6% MnO2 additive has the best Pcv when worked at frequencies higher than 1 MHz.
