03-type layered oxide serves as dominant components in sodium ion batteries;however,the unstable electronic structure between transition metal and oxygen inevitably induces framework instability and severe kinetic hin...03-type layered oxide serves as dominant components in sodium ion batteries;however,the unstable electronic structure between transition metal and oxygen inevitably induces framework instability and severe kinetic hindrance.In this study,a two-in-one approach to synergistically modulate the local electro nic and interfacial structure of NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)by Ce modification is proposed.We present an indepth study to reveal the strong-covalent Ce-O bonds,which make local charge around oxygen more negative,enhance O 2p-Mn 3d hybridization,and preserve the octahedral structural integrity.This modification tailors local electronic structure between the octahedral metal center and oxygen,thus enhancing reversibility of 03-P3-03 phase transition and expanding Na+octahedral-tetrahedral-octahedral transport channel.Additionally,the nanoscale perovskite layer induced by Ce element is in favor of minimizing interfacial side reaction as well as enhancing Na^(+)diffusivity.As a result,the designed 03-NaNi_(0.305)Fe_(0.33)Mn_(0.33)Ce_(0.025)O_(2)material delivers an exceptionally low volume variation,an ultrahigh rate capacity of 76.9 mA h g^(-1)at 10 C,and remarkable cycling life over 250 cycles with capacity retention of 80% at 5 C.展开更多
Structure and electrochemical properties of (La, Ce, Pr, Nd)_2MgNi_9 hydrogen storage alloys were investigated through orthogonal design experiments, and the alloys were obtained through induction melting followed by ...Structure and electrochemical properties of (La, Ce, Pr, Nd)_2MgNi_9 hydrogen storage alloys were investigated through orthogonal design experiments, and the alloys were obtained through induction melting followed by annealing treatment. The structure of main phase in alloys belongs to PuNi_3-type with a space group R3m. Rare earth elements, as a substitute of lanthanum, have a significant effect on phase structure of alloys, elements of cerium and neodymium are beneficial to the formation of Gd_2Co_7-type phase with a space group P 6_3/mmc. Rare earth elements can decrease the unit cell volume of main phase of alloys dramatically, and increase the axis ratio. The results of electrochemical experiment showed that the discharge capacity of alloy electrodes ranged from 342.97 to 380.68 mAh·g -1, and elements of cerium and neodymium can reduce the discharge capacity of alloy electrodes significantly. Compared to the electrode of La_2MgNi_9 alloy, the substitution of lanthanum by rare earth elements did not improve the cyclic stability of alloy electrodes due to the anisotropic structure change of unit cell. While rare-earth elements can improve the high rate dischargeability of alloy electrodes, the high rate dischargeability of alloy electrodes could reach the maximum when the unit cell volume of PuNi_3-type structure was about 0532 nm.展开更多
Sodium-ion batteries(SIBs)have recently gained wildly interest due to the abundance of sodium,lower production costs,and better low-temperature performance compared to lithium-ion batteries(LIBs).Among various cathode...Sodium-ion batteries(SIBs)have recently gained wildly interest due to the abundance of sodium,lower production costs,and better low-temperature performance compared to lithium-ion batteries(LIBs).Among various cathode materials of SIBs,O_(3)-type NaNi_(0.4)Fe_(0.2)Mn_(0.4)O_(2)(NFM424)demonstrates high capacity and ease of synthesis,yet suffers from structural degradation and sluggish Na^(+)kinetics caused by large ionic radius and strong electrostatic interactions.To overcome these issues,a configuration strategy combined with TiO_(2) and Co_(3)O_(4) by a simple solid-state reaction method was introduced to improve structural and electrochemical stability.XRD,SEM,TEM,and various electrochemical characterizations as well as TGA/DSC tests were conducted.The resulting NaNi_(0.4)Fe_(0.2)Mn_(0.3)Co_(0.05)Ti_(0.05)O_(2)(NFMCT)cathode mitigated Jahn-Teller distortions and Na^(+)/vacancy ordering while enhancing phase integrity and diffusion pathways.The obtained NFMCT maintained 93.7 mAh·g^(−1) after 550 cycles at 1 C,with superior rate capabilities at 2 C and 5 C.These findings deepen the understanding of configuration strategy by using multi-element oxide and highlight a practical strategy for designing high-performance SIB cathodes.展开更多
The development of high-performance cathode materials is critical to the practical application of sodiumion batteries(SIBs).O3-type NaCrO_(2)(NCO)is one of the most competitive cathodes,but it suffers from rapid capac...The development of high-performance cathode materials is critical to the practical application of sodiumion batteries(SIBs).O3-type NaCrO_(2)(NCO)is one of the most competitive cathodes,but it suffers from rapid capacity decay caused by severe irreversible structural evolution.An Mg-Ti co-doped Na_(0.99)Cr_(0.95)Mg_(0.02)Ti_(0.03)O_(2)(NCO-MT)cathode material is designed and synthesized via a facile solid-state reaction to enhance the cyclability of NCO.A capacity retention of 71.6%after 2500 cycles with the capacity fade rate of 0.011%per cycle is achieved for NCO-MT at 5 C,which is attributed to the highly reversible crystal structure during cycling.Our findings offer a novel insight into the high-performance O3-type layered cathode materials for SIBs and are beneficial to promote the development of high-rate SIBs.展开更多
Nonlinear optical(NLO)materials as a crucial part of the laser science have attracted increasing attention from researchers because of their wide applications in information storages,modern science and technologies,et...Nonlinear optical(NLO)materials as a crucial part of the laser science have attracted increasing attention from researchers because of their wide applications in information storages,modern science and technologies,et al.Based on the anionic group theory,theπ-conjugated 6-membered rings(6-MRs),B_(3)O_(6)-typed structures have key contributions to the superior optical properties ofβ-Ba_(2)B_(2)O_(4)(β-BBO).In recent years,the organic coplanarπ-conjugated B_(3)O_(6)-typed structures have caught researchers'attention due to similar configurations to the(B_(3)O_(6))groups,which are the potential sources for expending the(B_(3)O_(6))groups with outstanding optical properties.Up to know,researchers have obtained many ultraviolet(UV)NLO crystals with excellent properties withπ-conju-gated B_(3)O_(6)-typed groups.Herein,these B_(3)O_(6)-typed groups could be divided into different categories according to the atoms constituting the 6-MRs:(H_(x)C_(3)N_(3)O_(3))^(x-3)(x=0-3)(cyanurate ion),(H_(x)C_(4)N_(2)O_(3))^(x-4)(x=2,3)(barbi-turate ion),(C_(3)H_(7)N_(6))^(+)(melamine ion),(C_(5)H_(6)ON)^(+)(4-hydroxypyridine cation),and(C_(4)H_(6)N_(3))^(+)(2-amino-pyrimidinium cation).In this review,we introduced the research advances of NLO materials withπ-conjugated B_(3)O_(6)-typed groups,and summarized the crystal structures,synthetic methods,optical performances,as well as the relationships between structures and properties.This work provided a clear perspective for understanding the coplanarπ-conjugated B_(3)O_(6)-typed groups with their optical functional properties and promote the searches to develop potential NLO functional crystals.展开更多
Energy-storage systems and their production have attracted significant interest for practical applications.Batteries are the foundation of sustainable energy sources for electric vehicles(EVs),portable electronic devi...Energy-storage systems and their production have attracted significant interest for practical applications.Batteries are the foundation of sustainable energy sources for electric vehicles(EVs),portable electronic devices(PEDs),etc.In recent decades,Lithium-ion batteries(LIBs) have been extensively utilized in largescale energy storage devices owing to their long cycle life and high energy density.However,the high cost and limited availability of Li are the two main obstacles for LIBs.In this regard,sodium-ion batteries(SIBs) are attractive alternatives to LIBs for large-scale energy storage systems because of the abundance and low cost of sodium materials.Cathode is one of the most important components in the battery,which limits cost and performance of a battery.Among the classified cathode structures,layered structure materials have attracted attention because of their high ionic conductivity,fast diffusion rate,and high specific capacity.Here,we present a comprehensive review of the classification of layered structures and the preparation of layered materials.Furthermore,the review article discusses extensively about the issues of the layered materials,namely(1) electrochemical degradation,(2) irreversible structural changes,and(3) structural instability,and also it provides strategies to overcome the issues such as elemental phase composition,a small amount of elemental doping,structural design,and surface alteration for emerging SIBs.In addition,the article discusses about the recent research development on layered unary,binary,ternary,quaternary,quinary,and senary-based O3-and P2-type cathode materials for high-energy SIBs.This review article provides useful information for the development of high-energy layered sodium transition metal oxide P2 and O3-cathode materials for practical SIBs.展开更多
Potassium-ions batteries(PIBs)are attracting increasing attention as up-and-coming youngster in largescale grid-level energy storage benefiting from its low-cost and high energy density.Nevertheless,enough researches ...Potassium-ions batteries(PIBs)are attracting increasing attention as up-and-coming youngster in largescale grid-level energy storage benefiting from its low-cost and high energy density.Nevertheless,enough researches regarding indispensable cathode materials for PIBs are badly absent.Herein,we synthesize K-deficient layered manganese-based oxides(P2-K_(0.21)MnO_(2) and P3-K_(0.23)MnO_(2))and investigate them as cathode of PIBs for the first time.As the newcomer of potassium-containing layered manganese-based oxides(K_(x)MnO_(2))group,P2-K_(0.21)MnO_(2) delivers high discharge capacity of 99.3 mAh g^(-1) and P3-K_(0.23)MnO_(2) exhibits remarkable capacity retention rate of 75.5%.Besides,in-situ XRD and ex-situ XRD measurements reveal the reversible phase transition of P2-K_(0.21)MnO_(2) and P3-K_(0.23)MnO_(2) with the potassium-ions extraction and reinsertion,respectively.This work contributes to a better understanding for the potassium storage in K-deficient layered K_(x)MnO_(2)(x≤0.23),possessing an important basic scientific significance for the exploitation and application of layered K_(x)MnO_(2) in PIBs.展开更多
基金supported by the Science and technology plan project of Yulin(2023-CXY-193)the Project funded by Shaanxi Postdoctoral Science Foundation(2023BSHEDZZ274)+2 种基金the Shaanxi Province(2023-ZDLGY-24,2023-JC-QN-0588,Z20210201)the Science and technology plan project of Beilin(GX2319)the Science and technology plan project of Ankang(AK2023-GY-08)。
文摘03-type layered oxide serves as dominant components in sodium ion batteries;however,the unstable electronic structure between transition metal and oxygen inevitably induces framework instability and severe kinetic hindrance.In this study,a two-in-one approach to synergistically modulate the local electro nic and interfacial structure of NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)by Ce modification is proposed.We present an indepth study to reveal the strong-covalent Ce-O bonds,which make local charge around oxygen more negative,enhance O 2p-Mn 3d hybridization,and preserve the octahedral structural integrity.This modification tailors local electronic structure between the octahedral metal center and oxygen,thus enhancing reversibility of 03-P3-03 phase transition and expanding Na+octahedral-tetrahedral-octahedral transport channel.Additionally,the nanoscale perovskite layer induced by Ce element is in favor of minimizing interfacial side reaction as well as enhancing Na^(+)diffusivity.As a result,the designed 03-NaNi_(0.305)Fe_(0.33)Mn_(0.33)Ce_(0.025)O_(2)material delivers an exceptionally low volume variation,an ultrahigh rate capacity of 76.9 mA h g^(-1)at 10 C,and remarkable cycling life over 250 cycles with capacity retention of 80% at 5 C.
文摘Structure and electrochemical properties of (La, Ce, Pr, Nd)_2MgNi_9 hydrogen storage alloys were investigated through orthogonal design experiments, and the alloys were obtained through induction melting followed by annealing treatment. The structure of main phase in alloys belongs to PuNi_3-type with a space group R3m. Rare earth elements, as a substitute of lanthanum, have a significant effect on phase structure of alloys, elements of cerium and neodymium are beneficial to the formation of Gd_2Co_7-type phase with a space group P 6_3/mmc. Rare earth elements can decrease the unit cell volume of main phase of alloys dramatically, and increase the axis ratio. The results of electrochemical experiment showed that the discharge capacity of alloy electrodes ranged from 342.97 to 380.68 mAh·g -1, and elements of cerium and neodymium can reduce the discharge capacity of alloy electrodes significantly. Compared to the electrode of La_2MgNi_9 alloy, the substitution of lanthanum by rare earth elements did not improve the cyclic stability of alloy electrodes due to the anisotropic structure change of unit cell. While rare-earth elements can improve the high rate dischargeability of alloy electrodes, the high rate dischargeability of alloy electrodes could reach the maximum when the unit cell volume of PuNi_3-type structure was about 0532 nm.
基金funded by the National Natural Science Foundation of China(Grants 21701083 and 22179054)Jiangsu Provincial Key Research and Development Program(BZ2023010)2023 Jiangsu Government Scholarship for Overseas Studies.
文摘Sodium-ion batteries(SIBs)have recently gained wildly interest due to the abundance of sodium,lower production costs,and better low-temperature performance compared to lithium-ion batteries(LIBs).Among various cathode materials of SIBs,O_(3)-type NaNi_(0.4)Fe_(0.2)Mn_(0.4)O_(2)(NFM424)demonstrates high capacity and ease of synthesis,yet suffers from structural degradation and sluggish Na^(+)kinetics caused by large ionic radius and strong electrostatic interactions.To overcome these issues,a configuration strategy combined with TiO_(2) and Co_(3)O_(4) by a simple solid-state reaction method was introduced to improve structural and electrochemical stability.XRD,SEM,TEM,and various electrochemical characterizations as well as TGA/DSC tests were conducted.The resulting NaNi_(0.4)Fe_(0.2)Mn_(0.3)Co_(0.05)Ti_(0.05)O_(2)(NFMCT)cathode mitigated Jahn-Teller distortions and Na^(+)/vacancy ordering while enhancing phase integrity and diffusion pathways.The obtained NFMCT maintained 93.7 mAh·g^(−1) after 550 cycles at 1 C,with superior rate capabilities at 2 C and 5 C.These findings deepen the understanding of configuration strategy by using multi-element oxide and highlight a practical strategy for designing high-performance SIB cathodes.
基金financially supported by National Key Research and Development Program of China(No.2022YFE0202400)the National Natural Science Foundation of China(No.22379103)+2 种基金Natural Science Foundation of Guangdong Province of China(No.2021A1515010388)the Science and Technology Projects of Suzhou City(No.SYC2022043)the Qing Lan Project of Jiangsu Province(2022)。
文摘The development of high-performance cathode materials is critical to the practical application of sodiumion batteries(SIBs).O3-type NaCrO_(2)(NCO)is one of the most competitive cathodes,but it suffers from rapid capacity decay caused by severe irreversible structural evolution.An Mg-Ti co-doped Na_(0.99)Cr_(0.95)Mg_(0.02)Ti_(0.03)O_(2)(NCO-MT)cathode material is designed and synthesized via a facile solid-state reaction to enhance the cyclability of NCO.A capacity retention of 71.6%after 2500 cycles with the capacity fade rate of 0.011%per cycle is achieved for NCO-MT at 5 C,which is attributed to the highly reversible crystal structure during cycling.Our findings offer a novel insight into the high-performance O3-type layered cathode materials for SIBs and are beneficial to promote the development of high-rate SIBs.
基金supported by the National Natural Science Foundation of China(Grant Nos.22222510,21975255 and 21921001)the Foundation of Fujian Science&Technology Innovation Laboratory(2021ZR202)Youth Innovation Promotion Association CAS(2019303).
文摘Nonlinear optical(NLO)materials as a crucial part of the laser science have attracted increasing attention from researchers because of their wide applications in information storages,modern science and technologies,et al.Based on the anionic group theory,theπ-conjugated 6-membered rings(6-MRs),B_(3)O_(6)-typed structures have key contributions to the superior optical properties ofβ-Ba_(2)B_(2)O_(4)(β-BBO).In recent years,the organic coplanarπ-conjugated B_(3)O_(6)-typed structures have caught researchers'attention due to similar configurations to the(B_(3)O_(6))groups,which are the potential sources for expending the(B_(3)O_(6))groups with outstanding optical properties.Up to know,researchers have obtained many ultraviolet(UV)NLO crystals with excellent properties withπ-conju-gated B_(3)O_(6)-typed groups.Herein,these B_(3)O_(6)-typed groups could be divided into different categories according to the atoms constituting the 6-MRs:(H_(x)C_(3)N_(3)O_(3))^(x-3)(x=0-3)(cyanurate ion),(H_(x)C_(4)N_(2)O_(3))^(x-4)(x=2,3)(barbi-turate ion),(C_(3)H_(7)N_(6))^(+)(melamine ion),(C_(5)H_(6)ON)^(+)(4-hydroxypyridine cation),and(C_(4)H_(6)N_(3))^(+)(2-amino-pyrimidinium cation).In this review,we introduced the research advances of NLO materials withπ-conjugated B_(3)O_(6)-typed groups,and summarized the crystal structures,synthetic methods,optical performances,as well as the relationships between structures and properties.This work provided a clear perspective for understanding the coplanarπ-conjugated B_(3)O_(6)-typed groups with their optical functional properties and promote the searches to develop potential NLO functional crystals.
基金supported by a grant from the Subway Fine Dust Reduction Technology Development Project of the Ministry of Land Infrastructure and Transport,Republic of Korea(21QPPWB152306-03)the Basic Science Research Capacity Enhancement Project through a Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Ministry of Education of the Republic of Korea(2019R1A6C1010016)。
文摘Energy-storage systems and their production have attracted significant interest for practical applications.Batteries are the foundation of sustainable energy sources for electric vehicles(EVs),portable electronic devices(PEDs),etc.In recent decades,Lithium-ion batteries(LIBs) have been extensively utilized in largescale energy storage devices owing to their long cycle life and high energy density.However,the high cost and limited availability of Li are the two main obstacles for LIBs.In this regard,sodium-ion batteries(SIBs) are attractive alternatives to LIBs for large-scale energy storage systems because of the abundance and low cost of sodium materials.Cathode is one of the most important components in the battery,which limits cost and performance of a battery.Among the classified cathode structures,layered structure materials have attracted attention because of their high ionic conductivity,fast diffusion rate,and high specific capacity.Here,we present a comprehensive review of the classification of layered structures and the preparation of layered materials.Furthermore,the review article discusses extensively about the issues of the layered materials,namely(1) electrochemical degradation,(2) irreversible structural changes,and(3) structural instability,and also it provides strategies to overcome the issues such as elemental phase composition,a small amount of elemental doping,structural design,and surface alteration for emerging SIBs.In addition,the article discusses about the recent research development on layered unary,binary,ternary,quaternary,quinary,and senary-based O3-and P2-type cathode materials for high-energy SIBs.This review article provides useful information for the development of high-energy layered sodium transition metal oxide P2 and O3-cathode materials for practical SIBs.
基金support from the Key Project of Guangdong Province Nature Science Foundation (No. 2017B030311013)the Scientific and Technological Plan of Guangdong Province, Guangzhou and Qingyuan City, China (Nos. 2019B090905005, 2019B090911004, 2017B020227009, 2019DZX008, 2019A004)+2 种基金the financial support from the National Key R&D Program of China (2018YFB1502600)the National Natural Science Foundation of China (No. 51922042 and 51872098)the Sino-Singapore International Joint Research Institute (SSIJRI), Guangzhou 510700, China.
文摘Potassium-ions batteries(PIBs)are attracting increasing attention as up-and-coming youngster in largescale grid-level energy storage benefiting from its low-cost and high energy density.Nevertheless,enough researches regarding indispensable cathode materials for PIBs are badly absent.Herein,we synthesize K-deficient layered manganese-based oxides(P2-K_(0.21)MnO_(2) and P3-K_(0.23)MnO_(2))and investigate them as cathode of PIBs for the first time.As the newcomer of potassium-containing layered manganese-based oxides(K_(x)MnO_(2))group,P2-K_(0.21)MnO_(2) delivers high discharge capacity of 99.3 mAh g^(-1) and P3-K_(0.23)MnO_(2) exhibits remarkable capacity retention rate of 75.5%.Besides,in-situ XRD and ex-situ XRD measurements reveal the reversible phase transition of P2-K_(0.21)MnO_(2) and P3-K_(0.23)MnO_(2) with the potassium-ions extraction and reinsertion,respectively.This work contributes to a better understanding for the potassium storage in K-deficient layered K_(x)MnO_(2)(x≤0.23),possessing an important basic scientific significance for the exploitation and application of layered K_(x)MnO_(2) in PIBs.
