P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)(NNMO)is promising cathode material for sodium-ion batteries(SIBs)due to its high specific capacity and fast Na+diffusion rate.Nonetheless,the irreversible P2-O_(2)phase transformati...P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)(NNMO)is promising cathode material for sodium-ion batteries(SIBs)due to its high specific capacity and fast Na+diffusion rate.Nonetheless,the irreversible P2-O_(2)phase transformation,Na+/vacancy ordering,and transition metal(TM)dissolution seriously damage its cycling stability and restrict its commercialization process.Herein,Na occupation manipulation and interface stabilization are proposed to strengthen the phase structure of NNMO by synergistic Zn/Ti co-doping and introducing lithium difluorophosp(LiPO_(2)F_(2))film-forming electrolyte additive.The Zn/Ti co-doping regulates the occupancy ratio of Nae/Nafat Na sites and disorganizes the Na+/vacancy ordering,resulting in a faster Na+diffusion kinetics and reversible P2-Z phase transition for P2-Na_(0.67)Ni_(0.28)Zn_(0.05)Mn_(0.62)Ti_(0.05)O_(2)(NNZMTO).Meanwhile,the LiPO_(2)F_(2)additive can form homogeneous and ultrathin cathode-electrolyte interphase(CEI)on NNZMTO surface,which can stabilize the NNZMTO-electrolyte interface to prevent TM dissolution,surface structure transformation,and micro-crack generation.Combination studies of in situ and ex situ characterizations and theoretical calculations were used to elucidate the storage mechanism of NNZMTO with Li PO_(2)F_(2)additive.As a result,the NNZMTO displays outstanding capacity retention of 94.44%after 500 cycles at 1C with 0.3 wt%Li PO_(2)F_(2),excellent rate performance of 92.5 mA h g^(-1)at 8C with 0.1 wt%Li PO_(2)F_(2),and remarkable full cell capability.This work highlights the important role of manipulating Na occupation and constructing protective film in the design of layered materials,which provides a promising direction for developing high-performance cathodes for SIBs.展开更多
Hot-dip Zn-Ti galvanizing can restrain the excess growth of the coating which has better corrosion resist- ances than hot-dip pure Zn. The change rules of Г2 intermetallic compound in hot-dip Zn-Ti galvanizing is inv...Hot-dip Zn-Ti galvanizing can restrain the excess growth of the coating which has better corrosion resist- ances than hot-dip pure Zn. The change rules of Г2 intermetallic compound in hot-dip Zn-Ti galvanizing is investiga ted by immersion time, titanium content and the slag test using scanning electron microscopy （SEM）, energy dis- persive spectroscopy （EDS） and X-ray diffraction （XRD）. And the mechanism of nucleation and growth of Г2 inter- metallic compound is analysed. The results show that, when adding 0. 05mass% titanium to the zinc bath, the Г2 particles form in the η layer, which nucleate by obtaining Ti atoms from the phase and Fe atoms from the dissol- ving ζ phase layer. Moreover, the more titanium is added into the bath, the more and bigger Гz particles appear. The Fz particles in the coatings grow up noticeably with prolonging the immersion time.展开更多
Mn-based zinc ion battery has the advantages of low cost and high performance,which makes it the promising energy storage system.However,the poor conductivity and the agglomeration in the synthesis process of manganes...Mn-based zinc ion battery has the advantages of low cost and high performance,which makes it the promising energy storage system.However,the poor conductivity and the agglomeration in the synthesis process of manganese-based materials restrict the performance of batteries.Herein,the Se-doped MnS/Ti_(3)C_(2)T_(x)(Se-MnS/Ti_(3)C_(2)T_(x))composite material derived from Mn-based metal-organic framework is reported.Electrochemical tests show that Se-doped could generate S defects and enhance the electrochemical activity of MnS.At the same time,the introduction of Ti_(3)C_(2)T_(x) substrate is conducive to exposing more sulfur defects and improving the utilization rate of defects.In the mechanism study,it is found that Se-MnS/Ti_(3)C_(2)T_(x) is transformed into S/Se co-doped Mn3O_(4) at the first charge,which innovatively elucidated the behavior of S/Se during activation.In the electrochemical performance test,the specific capacity can reach 74.7 mAh·g^(-1) at 5.0 A·g^(-1).In addition,the Zn-Ti_(3)C_(2)T_(x) membrane electrode is prepared by vacuum filtration as the zinc-poor anode,which is assembled into the rocking chair full battery to avoid dendrite growth and exhibit excellent rate performance.The addition of Zn2+weakens the electrostatic repulsion between the interlayers of MXene,and the formation of the folded morphology aids the penetration of the electrolyte.At 1.0 A·g^(-1),the capacity can reach 50.6 mAh·g^(-1).This work is helpful to promote the research and development of the reaction mechanism of manganese based rocking chair batteries.展开更多
基金supported by the Natural Science Foundation of Shandong Province (ZR2023MB017,ZR2021QB055,ZR2020QB014,ZR2022JQ10)the National Natural Science Foundation of China (21901146,220781792,52007110)the Taishan Scholar Foundation (tsqn201812063)。
文摘P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)(NNMO)is promising cathode material for sodium-ion batteries(SIBs)due to its high specific capacity and fast Na+diffusion rate.Nonetheless,the irreversible P2-O_(2)phase transformation,Na+/vacancy ordering,and transition metal(TM)dissolution seriously damage its cycling stability and restrict its commercialization process.Herein,Na occupation manipulation and interface stabilization are proposed to strengthen the phase structure of NNMO by synergistic Zn/Ti co-doping and introducing lithium difluorophosp(LiPO_(2)F_(2))film-forming electrolyte additive.The Zn/Ti co-doping regulates the occupancy ratio of Nae/Nafat Na sites and disorganizes the Na+/vacancy ordering,resulting in a faster Na+diffusion kinetics and reversible P2-Z phase transition for P2-Na_(0.67)Ni_(0.28)Zn_(0.05)Mn_(0.62)Ti_(0.05)O_(2)(NNZMTO).Meanwhile,the LiPO_(2)F_(2)additive can form homogeneous and ultrathin cathode-electrolyte interphase(CEI)on NNZMTO surface,which can stabilize the NNZMTO-electrolyte interface to prevent TM dissolution,surface structure transformation,and micro-crack generation.Combination studies of in situ and ex situ characterizations and theoretical calculations were used to elucidate the storage mechanism of NNZMTO with Li PO_(2)F_(2)additive.As a result,the NNZMTO displays outstanding capacity retention of 94.44%after 500 cycles at 1C with 0.3 wt%Li PO_(2)F_(2),excellent rate performance of 92.5 mA h g^(-1)at 8C with 0.1 wt%Li PO_(2)F_(2),and remarkable full cell capability.This work highlights the important role of manipulating Na occupation and constructing protective film in the design of layered materials,which provides a promising direction for developing high-performance cathodes for SIBs.
基金Sponsored by Science and Technology Planning Project of Guangdong Province of China(2011B010300017)
文摘Hot-dip Zn-Ti galvanizing can restrain the excess growth of the coating which has better corrosion resist- ances than hot-dip pure Zn. The change rules of Г2 intermetallic compound in hot-dip Zn-Ti galvanizing is investiga ted by immersion time, titanium content and the slag test using scanning electron microscopy （SEM）, energy dis- persive spectroscopy （EDS） and X-ray diffraction （XRD）. And the mechanism of nucleation and growth of Г2 inter- metallic compound is analysed. The results show that, when adding 0. 05mass% titanium to the zinc bath, the Г2 particles form in the η layer, which nucleate by obtaining Ti atoms from the phase and Fe atoms from the dissol- ving ζ phase layer. Moreover, the more titanium is added into the bath, the more and bigger Гz particles appear. The Fz particles in the coatings grow up noticeably with prolonging the immersion time.
基金supported by the National Natural Science Foundation of China(No.51962032)the program for Strong Youth Technology Leading Talents in Bingtuan Technological Innovation Talents(No.2023CB00811)+2 种基金Youth Innovation Promotion Association CAS(No.2021433)the Youth Innovative Top Talents Fund,Shihezi University(No.CXBJ202203)Youth Science and Technology Innovation Leading Talent Fund,Bashi Shihezi(No.2023RC02).
文摘Mn-based zinc ion battery has the advantages of low cost and high performance,which makes it the promising energy storage system.However,the poor conductivity and the agglomeration in the synthesis process of manganese-based materials restrict the performance of batteries.Herein,the Se-doped MnS/Ti_(3)C_(2)T_(x)(Se-MnS/Ti_(3)C_(2)T_(x))composite material derived from Mn-based metal-organic framework is reported.Electrochemical tests show that Se-doped could generate S defects and enhance the electrochemical activity of MnS.At the same time,the introduction of Ti_(3)C_(2)T_(x) substrate is conducive to exposing more sulfur defects and improving the utilization rate of defects.In the mechanism study,it is found that Se-MnS/Ti_(3)C_(2)T_(x) is transformed into S/Se co-doped Mn3O_(4) at the first charge,which innovatively elucidated the behavior of S/Se during activation.In the electrochemical performance test,the specific capacity can reach 74.7 mAh·g^(-1) at 5.0 A·g^(-1).In addition,the Zn-Ti_(3)C_(2)T_(x) membrane electrode is prepared by vacuum filtration as the zinc-poor anode,which is assembled into the rocking chair full battery to avoid dendrite growth and exhibit excellent rate performance.The addition of Zn2+weakens the electrostatic repulsion between the interlayers of MXene,and the formation of the folded morphology aids the penetration of the electrolyte.At 1.0 A·g^(-1),the capacity can reach 50.6 mAh·g^(-1).This work is helpful to promote the research and development of the reaction mechanism of manganese based rocking chair batteries.
