CsPbI_(2)Br perovskite solar cells have achieved rapid development owing to their exceptional optoelectronic properties and relatively outstanding stability.However,open-circuit voltage(Voc)loss caused by band mismatc...CsPbI_(2)Br perovskite solar cells have achieved rapid development owing to their exceptional optoelectronic properties and relatively outstanding stability.However,open-circuit voltage(Voc)loss caused by band mismatch and charge recombination between perovskite and charge transporting layer is one of the crucial obstacles to further improve the device performance.Here,we proposed a bilayer electron transport layer ZnO(bottom)/SnO_(2)(top)to reduce the Voc loss(Eloss)and promote device Voc by ZnO insert layer thickness modulation,which could improve the efficiency of charge carrier extraction/transfer and suppress the charge carrier recombination.In addition,guanidinium iodide top surface treatment is used to further reduce the trap density,stabilize the perovskite film and align the energy levels,which promotes the fill factor,short-circuit current density(Jsc),and stability of the device.As a result,the champion cell of double-side optimized CsPbI_(2)Br perovskite solar cells exhibits an extraordinary efficiency of 16.25%with the best Voc as high as 1.27 V and excellent thermal and storage stability.展开更多
Increasing the charging cut-off voltage can significantly enhance the energy density of LiCoO_(2).However,the continuous deterioration of interface structure and transport kinetics under high voltage poses challenges ...Increasing the charging cut-off voltage can significantly enhance the energy density of LiCoO_(2).However,the continuous deterioration of interface structure and transport kinetics under high voltage poses challenges to electrochemical stability.This work proposes to in-situ construct a uniform element gradient modification structure on the surface and subsurface of LiCoO_(2).The modification structure contains an Sb_(2)O_(3)&SbF_(x)composite coating layer and an Sb-F doped spinel-like transition layer,simultaneously.The modified sample maintains an initial discharge specific capacity of 221.2 mA h g^(-1)and a capacity retention of 86%after 200 cycles at 3–4.6 V and 0.5 C.Moreover,it has a discharge specific capacity of163.3 mA h g^(-1)at a high rate of 5 C.Meanwhile,combining highly electronegative Sb^(3+)&F^(-)that widen the Li^(+)transport channel with the amorphous coating of F^(-)doped Sb_(2)O_(3)with higher conductivity improves the interface transport kinetics.This breaks the stereotypical view in traditional concepts that fluorinated coatings or inert metal oxide coatings inhibit Li^(+)transport.Moreover,the inert composite coating combined with Sb–O–F with high bond energy stabilizes the surface structure.A series of characterizations confirm that the joint improvement of interface structure stability and transport kinetics significantly enhances the electrochemical performance of LiCoO_(2).展开更多
Weakly-solvated electrolytes(WSEs)utilizing solvents with weak coordination ability offer advantages for low-potential graphite anode owing to their facile desolvation process and anions-derived inorganic-rich solid e...Weakly-solvated electrolytes(WSEs)utilizing solvents with weak coordination ability offer advantages for low-potential graphite anode owing to their facile desolvation process and anions-derived inorganic-rich solid electrolyte interphase(SEI)film.However,these electrolytes face challenges in achieving a balance between the weak solvation affinity and high ionic conductivity,as well as between rigid inorganic-rich SEI and flexible SEI for long-term stability.Herein,we introduce 1,3-dioxolane(DOL)and lithium bis(trifluoromethanesulfonyl)-imide(LiTFSI)as functional additives into a WSE based on nonpolar cyclic ether(1,4-dioxane).The well-formulated WSE not only preserves the weakly solvated features and anion-dominated solvation sheath,but also utilizes DOL to contribute organic species for stabilizing the SEI layer.Benefitting from these merits,the optimized electrolyte enables graphite anode with excellent fast-charging performance(210 mAh/g at 5 C)and outstanding cycling stability(600 cycles with a capacity retention of 82.0%at room temperature and 400 cycles with a capacity retention of 80.4%at high temper-ature).Furthermore,the fabricated LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)||graphite full cells demonstrate stable operation for 140 cycles with high capacity retention of 80.3%.This work highlights the potential of tailoring solvation sheath and interphase properties in WSEs for advanced electrolyte design in graphite-based lithium-ion batteries.展开更多
基金supported by National Natural Science Foundation of China(61704131 and 61804111)National Key Research and Development Program of China(Grant 2018YFB2202900)+2 种基金Key Research and Development Program of Shaanxi Province(Grant 2020GY-310)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-018)the Fundamental Research Funds for the Central Universities and the Innovation Fund of Xidian University.
文摘CsPbI_(2)Br perovskite solar cells have achieved rapid development owing to their exceptional optoelectronic properties and relatively outstanding stability.However,open-circuit voltage(Voc)loss caused by band mismatch and charge recombination between perovskite and charge transporting layer is one of the crucial obstacles to further improve the device performance.Here,we proposed a bilayer electron transport layer ZnO(bottom)/SnO_(2)(top)to reduce the Voc loss(Eloss)and promote device Voc by ZnO insert layer thickness modulation,which could improve the efficiency of charge carrier extraction/transfer and suppress the charge carrier recombination.In addition,guanidinium iodide top surface treatment is used to further reduce the trap density,stabilize the perovskite film and align the energy levels,which promotes the fill factor,short-circuit current density(Jsc),and stability of the device.As a result,the champion cell of double-side optimized CsPbI_(2)Br perovskite solar cells exhibits an extraordinary efficiency of 16.25%with the best Voc as high as 1.27 V and excellent thermal and storage stability.
基金supported by the National Natural Science Foundation of China(22075170)employed resources from the BL11B station of the Shanghai Synchrotron Radiation Facility(SSRF,under contract number:2023-SSRF-PT-502681)。
文摘Increasing the charging cut-off voltage can significantly enhance the energy density of LiCoO_(2).However,the continuous deterioration of interface structure and transport kinetics under high voltage poses challenges to electrochemical stability.This work proposes to in-situ construct a uniform element gradient modification structure on the surface and subsurface of LiCoO_(2).The modification structure contains an Sb_(2)O_(3)&SbF_(x)composite coating layer and an Sb-F doped spinel-like transition layer,simultaneously.The modified sample maintains an initial discharge specific capacity of 221.2 mA h g^(-1)and a capacity retention of 86%after 200 cycles at 3–4.6 V and 0.5 C.Moreover,it has a discharge specific capacity of163.3 mA h g^(-1)at a high rate of 5 C.Meanwhile,combining highly electronegative Sb^(3+)&F^(-)that widen the Li^(+)transport channel with the amorphous coating of F^(-)doped Sb_(2)O_(3)with higher conductivity improves the interface transport kinetics.This breaks the stereotypical view in traditional concepts that fluorinated coatings or inert metal oxide coatings inhibit Li^(+)transport.Moreover,the inert composite coating combined with Sb–O–F with high bond energy stabilizes the surface structure.A series of characterizations confirm that the joint improvement of interface structure stability and transport kinetics significantly enhances the electrochemical performance of LiCoO_(2).
基金support from the National Key Research and Development Program of China(No.2022YFB2402200)National Natural Science Foundation of China(No.22109028)+1 种基金Natural Science Foundation of Shanghai(No.22ZR1404400)Chenguang Program sponsored by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.19CG01).
文摘Weakly-solvated electrolytes(WSEs)utilizing solvents with weak coordination ability offer advantages for low-potential graphite anode owing to their facile desolvation process and anions-derived inorganic-rich solid electrolyte interphase(SEI)film.However,these electrolytes face challenges in achieving a balance between the weak solvation affinity and high ionic conductivity,as well as between rigid inorganic-rich SEI and flexible SEI for long-term stability.Herein,we introduce 1,3-dioxolane(DOL)and lithium bis(trifluoromethanesulfonyl)-imide(LiTFSI)as functional additives into a WSE based on nonpolar cyclic ether(1,4-dioxane).The well-formulated WSE not only preserves the weakly solvated features and anion-dominated solvation sheath,but also utilizes DOL to contribute organic species for stabilizing the SEI layer.Benefitting from these merits,the optimized electrolyte enables graphite anode with excellent fast-charging performance(210 mAh/g at 5 C)and outstanding cycling stability(600 cycles with a capacity retention of 82.0%at room temperature and 400 cycles with a capacity retention of 80.4%at high temper-ature).Furthermore,the fabricated LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)||graphite full cells demonstrate stable operation for 140 cycles with high capacity retention of 80.3%.This work highlights the potential of tailoring solvation sheath and interphase properties in WSEs for advanced electrolyte design in graphite-based lithium-ion batteries.
