With the advantages of mature preparation technology,structural adjustability and suitability for large-scale application,Zn powder anode is considered to be an ideal electrode for realizing low-cost,high-energy-densi...With the advantages of mature preparation technology,structural adjustability and suitability for large-scale application,Zn powder anode is considered to be an ideal electrode for realizing low-cost,high-energy-density aqueous Zn metal batteries.However,the high specific surface of Zn powders leads to severe side reactions such as hydrogen evolution and corrosion,thus limiting their widespread use Here,this work develops a novel CuO@Zn powder anode with a synergy effect of surface wrapping and compositing.Zn powders are uniformly wrapped by small CuO particles due to the strong adsorption between Zn and CuO.The wrapped CuO particles build a good conductive framework to inhibit the structural collapse of the Zn powder caused by corrosion and non-uniform deposition.Meanwhile,CuO can also be used as a seed to guide the uniform deposition of Zn ions through its strong binding energy with Zn.As a result,the Cu O@Zn anode can maintain a long cyclic life of 900 h at current density of 1 mA·cm^(-2)and capacity of 1 mAh·cm^(-2),as well as contribute to an excellent capacity retention of 92% after 800cycles for CuO@Zn||NH_(4)V_(4)O_(10)full cell.Even at high current density of 5 A·g^(-1),the full cell exhibits a specific capacity of more than 200 mAh·g^(-1)after 800 cycles,with a good capacity retention of 89%.This work provides a new idea for developing high-performance Zn powder-based anodes.展开更多
Zn powder anodes have attracted much attention in aqueous Zn ion battery applications due to advantages such as low cost and processability.However,the high-activity Zn powder anode faces problems such as side reactio...Zn powder anodes have attracted much attention in aqueous Zn ion battery applications due to advantages such as low cost and processability.However,the high-activity Zn powder anode faces problems such as side reactions,hydrogen evolution,and dendrites,which limit the cycling stability of the cell.In this work,the high activity of Zn powder is weakened by introducing low-cost erythritol as a functional additive in the ZnSO_(4) electrolyte to improve the cycle life of the cell.Both theoretical calculations and empirical evidence demonstrate that the incorporation of erythritol alters the coordination sphere of Zn^(2+)and modifies the local molecular architecture of the electrolyte.This modification serves to diminish the reactivity of water molecules,thereby efficaciously suppressing dendrite formation and deleterious ancillary reactions on the zinc powder anode surfaces.Concurrently,erythritol functions as an interfacial cationic captor,enhancing reaction dynamics and facilitating the development of a favorable protective layer throughout the zinc plating/stripping process.Consequently,the symmetric cell paired with an erythritol-containing electrolyte manifests stable cycling performance for an extended duration of 850 h at a current density of 0.288 mA cm^(-2)and areal capacity of 0.144 mAh cm^(-2).Notably,it maintains a cycling life of 400 h even under intensified conditions (2.88 mA cm^(-2)/1.44 mA h cm^(-2)).Furthermore,the constructed Na_(2)V_(6)O_(16)·3H_(2)O full cell illustrated remarkable capacity retention of 155.8 mA h g^(-1)following 800 cycles at a high rate of 5 A g^(-1).展开更多
Mn-Zn spinel ferrites were synthesized by sol-gel method. Effects of calcined temperature on structure and particle size of MnZnFe2O4 were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM)...Mn-Zn spinel ferrites were synthesized by sol-gel method. Effects of calcined temperature on structure and particle size of MnZnFe2O4 were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD patterns indicate that the ultra fine Mn-Zn ferrite exhibits a spinel crystal structure. SEM images show that the powder fired at 900℃for 2 h has an average diameter of 60 ~ 90 nm. The particle size becomes larger with the increasing of calcined temperature and the distribution of particle becomes even more homogeneous. Sintering behaviors of synthesized ferrite powders depend on the powder characteristics and high temperatures have induced the good crystallization of particles.展开更多
The structure of Al-Mn-Zn-Mg alloy powder annealed at 800℃ has been studied by transmisston electron microscopy(TEM).An approximant phase(named as C-phase) to the decagonal phase was found and its crystal structure w...The structure of Al-Mn-Zn-Mg alloy powder annealed at 800℃ has been studied by transmisston electron microscopy(TEM).An approximant phase(named as C-phase) to the decagonal phase was found and its crystal structure was determined It belongs to c-center orthorhombic lattice with a=2.35 nm,b=3.27 nm and c=1.22 nm.We stillfound a hexagonal phase with a=0.7) nm and c=0.79 nm,(named as phase) in the annealed alloy powder.The annealed alloy powder is composed of the C-phase,the phase,the decagonal phase and Al solid solution.展开更多
We report a simple and green approach to synthesize reduced graphene oxide （RGO） nanosheets at room temperature based on Zn reduction of exfoliated GO. The evolution of GO to RGO has been characterized by X-ray diff...We report a simple and green approach to synthesize reduced graphene oxide （RGO） nanosheets at room temperature based on Zn reduction of exfoliated GO. The evolution of GO to RGO has been characterized by X-ray diffraction, UV-Vis absorption spectroscopy and Raman spectroscopy. The results of X-ray photoelectron spectroscopy reveal that the atomic ratio of carbon to oxygen in the RGO can be tuned from 1.67 to 13.7 through controlling the reduction time. Moreover, the conductivity of the RGO is measured to be 26.9±2.2 kS/m, much larger than those previously obtained by chemical reduction through other reducing agents. More importantly, the resistance of the RGO film with 20 nm thickhess can be as low as 2 kΩ/square, while a high transparency over 70% within a broad spectral range from 0.45 pm to 1.50 p.m can be retained. The proposed method is low-cost, eco-friendly and highly-eiffcient, the as-prepared thinner RGO films are useful in a variety of potential application fields such as optoelectronics, photovoltaics and electrochemistry by serving as an ultralight, flexible and transparent electrode material.展开更多
采用高能球磨法制备了用于热浸镀锌的纳米C eO2/Zn复合粉末,并利用X射线衍射(X-ray d iffraction,XRD)、X射线光电子能谱(X-ray photoe lectron spectroscopy,XPS)、透射电镜(T ransm iss ion e lectron m i-croscopy,TEM)、扫描电镜(Sc...采用高能球磨法制备了用于热浸镀锌的纳米C eO2/Zn复合粉末,并利用X射线衍射(X-ray d iffraction,XRD)、X射线光电子能谱(X-ray photoe lectron spectroscopy,XPS)、透射电镜(T ransm iss ion e lectron m i-croscopy,TEM)、扫描电镜(Scann ing e lectron m icroscopy,SEM)以及能谱分析(X-ray energy d ispers ive spec-trum,EDS)等方法,对复合粉末的显微结构、表面成分、晶粒大小、微观形貌以及元素分布进行了研究。结果表明,随着球磨时间的延长,纳米C eO2硬团聚体逐渐解聚,Zn晶粒不断细化,形成层片状复合粉末;球磨120 m in后纳米C eO2粒子分散良好,呈理想的单个均匀弥散分布状态包覆在Zn颗粒上形成近似球形的复合粒子,其粒径分布均匀。展开更多
基金financially supported by the National Natural Science Foundation of China(No.52072411)the Central South University Innovation-Driven Research Programme(No.2023CXQD038)。
文摘With the advantages of mature preparation technology,structural adjustability and suitability for large-scale application,Zn powder anode is considered to be an ideal electrode for realizing low-cost,high-energy-density aqueous Zn metal batteries.However,the high specific surface of Zn powders leads to severe side reactions such as hydrogen evolution and corrosion,thus limiting their widespread use Here,this work develops a novel CuO@Zn powder anode with a synergy effect of surface wrapping and compositing.Zn powders are uniformly wrapped by small CuO particles due to the strong adsorption between Zn and CuO.The wrapped CuO particles build a good conductive framework to inhibit the structural collapse of the Zn powder caused by corrosion and non-uniform deposition.Meanwhile,CuO can also be used as a seed to guide the uniform deposition of Zn ions through its strong binding energy with Zn.As a result,the Cu O@Zn anode can maintain a long cyclic life of 900 h at current density of 1 mA·cm^(-2)and capacity of 1 mAh·cm^(-2),as well as contribute to an excellent capacity retention of 92% after 800cycles for CuO@Zn||NH_(4)V_(4)O_(10)full cell.Even at high current density of 5 A·g^(-1),the full cell exhibits a specific capacity of more than 200 mAh·g^(-1)after 800 cycles,with a good capacity retention of 89%.This work provides a new idea for developing high-performance Zn powder-based anodes.
基金supported by the Hunan Chenyu Fuji New Energy Technology Co. Ltd (2022zkhx501)the Hunan Province University Teaching Reform and Research Project (HNJG-20230364)the Ministry of Education’s Industry-University Cooperation and Collaborative Talent Development Program(231106707093309)。
文摘Zn powder anodes have attracted much attention in aqueous Zn ion battery applications due to advantages such as low cost and processability.However,the high-activity Zn powder anode faces problems such as side reactions,hydrogen evolution,and dendrites,which limit the cycling stability of the cell.In this work,the high activity of Zn powder is weakened by introducing low-cost erythritol as a functional additive in the ZnSO_(4) electrolyte to improve the cycle life of the cell.Both theoretical calculations and empirical evidence demonstrate that the incorporation of erythritol alters the coordination sphere of Zn^(2+)and modifies the local molecular architecture of the electrolyte.This modification serves to diminish the reactivity of water molecules,thereby efficaciously suppressing dendrite formation and deleterious ancillary reactions on the zinc powder anode surfaces.Concurrently,erythritol functions as an interfacial cationic captor,enhancing reaction dynamics and facilitating the development of a favorable protective layer throughout the zinc plating/stripping process.Consequently,the symmetric cell paired with an erythritol-containing electrolyte manifests stable cycling performance for an extended duration of 850 h at a current density of 0.288 mA cm^(-2)and areal capacity of 0.144 mAh cm^(-2).Notably,it maintains a cycling life of 400 h even under intensified conditions (2.88 mA cm^(-2)/1.44 mA h cm^(-2)).Furthermore,the constructed Na_(2)V_(6)O_(16)·3H_(2)O full cell illustrated remarkable capacity retention of 155.8 mA h g^(-1)following 800 cycles at a high rate of 5 A g^(-1).
基金Project supported by the Fund for Harbin Young Scholars (2005AFQXJ031)
文摘Mn-Zn spinel ferrites were synthesized by sol-gel method. Effects of calcined temperature on structure and particle size of MnZnFe2O4 were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD patterns indicate that the ultra fine Mn-Zn ferrite exhibits a spinel crystal structure. SEM images show that the powder fired at 900℃for 2 h has an average diameter of 60 ~ 90 nm. The particle size becomes larger with the increasing of calcined temperature and the distribution of particle becomes even more homogeneous. Sintering behaviors of synthesized ferrite powders depend on the powder characteristics and high temperatures have induced the good crystallization of particles.
文摘The structure of Al-Mn-Zn-Mg alloy powder annealed at 800℃ has been studied by transmisston electron microscopy(TEM).An approximant phase(named as C-phase) to the decagonal phase was found and its crystal structure was determined It belongs to c-center orthorhombic lattice with a=2.35 nm,b=3.27 nm and c=1.22 nm.We stillfound a hexagonal phase with a=0.7) nm and c=0.79 nm,(named as phase) in the annealed alloy powder.The annealed alloy powder is composed of the C-phase,the phase,the decagonal phase and Al solid solution.
基金V. ACKNOWLEDGMENTS This work is supported by the Ministry of Science and Technologyh of China （No.2011CB921403）, the National Natural Science Foundation of China （No.10874165, No.90921013, No.11074231, and No.11004179） and Chinese Academy of Sciences .
文摘We report a simple and green approach to synthesize reduced graphene oxide （RGO） nanosheets at room temperature based on Zn reduction of exfoliated GO. The evolution of GO to RGO has been characterized by X-ray diffraction, UV-Vis absorption spectroscopy and Raman spectroscopy. The results of X-ray photoelectron spectroscopy reveal that the atomic ratio of carbon to oxygen in the RGO can be tuned from 1.67 to 13.7 through controlling the reduction time. Moreover, the conductivity of the RGO is measured to be 26.9±2.2 kS/m, much larger than those previously obtained by chemical reduction through other reducing agents. More importantly, the resistance of the RGO film with 20 nm thickhess can be as low as 2 kΩ/square, while a high transparency over 70% within a broad spectral range from 0.45 pm to 1.50 p.m can be retained. The proposed method is low-cost, eco-friendly and highly-eiffcient, the as-prepared thinner RGO films are useful in a variety of potential application fields such as optoelectronics, photovoltaics and electrochemistry by serving as an ultralight, flexible and transparent electrode material.
文摘采用高能球磨法制备了用于热浸镀锌的纳米C eO2/Zn复合粉末,并利用X射线衍射(X-ray d iffraction,XRD)、X射线光电子能谱(X-ray photoe lectron spectroscopy,XPS)、透射电镜(T ransm iss ion e lectron m i-croscopy,TEM)、扫描电镜(Scann ing e lectron m icroscopy,SEM)以及能谱分析(X-ray energy d ispers ive spec-trum,EDS)等方法,对复合粉末的显微结构、表面成分、晶粒大小、微观形貌以及元素分布进行了研究。结果表明,随着球磨时间的延长,纳米C eO2硬团聚体逐渐解聚,Zn晶粒不断细化,形成层片状复合粉末;球磨120 m in后纳米C eO2粒子分散良好,呈理想的单个均匀弥散分布状态包覆在Zn颗粒上形成近似球形的复合粒子,其粒径分布均匀。
