The rapid development and widespread application of lithium-ion batteries(LIBs) have increased demand for high-safety and high-performance LIBs. Accordingly, various additives have been used in commercial liquid elect...The rapid development and widespread application of lithium-ion batteries(LIBs) have increased demand for high-safety and high-performance LIBs. Accordingly, various additives have been used in commercial liquid electrolytes to severally adjust the solvation structure of lithium ions, control the components of solid electrolyte interphase, or reduce flammability. While it is highly desirable to develop low-cost multifunctional electrolyte additives integrally that address both safety and performance on LIBs, significant challenges remain. Herein, a novel phosphorus-containing organic small molecule, bis(2-methoxyethyl) methylphosphonate(BMOP), was rationally designed to serve as a fluorine-free and multifunctional additive in commercial electrolytes. This novel electrolyte additive is low-toxicity,high-efficiency, low-cost, and electrode-compatible, which shows the significant improvement to both electrochemical performance and fire safety for LIBs through regulating the electrolyte solvation structure, constructing the stable electrode-electrolyte interphase, and suppressing the electrolyte combustion. This work provides a new avenue for developing safer and high-performance LIBs.展开更多
The electrochemical performance of all-solid-state lithium batteries(ASSLBs)can be prominently enhanced by minimizing the detrimental degradation of solid electrolytes through their undesirable side reactions with the...The electrochemical performance of all-solid-state lithium batteries(ASSLBs)can be prominently enhanced by minimizing the detrimental degradation of solid electrolytes through their undesirable side reactions with the conductive carbon additives(CCAs)inside the composite cathodes.Herein,the well-defined Mo_(3)Ni_(3)N nanosheets embedded onto the N-doped porous carbons(NPCs)substrate are successfully synthesized(Mo-Ni@NPCs)as CCAs inside LiCoO_(2)for Li_(6)PSC_5)Cl(LPSCl)-based ASSLBs.This nano-composite not only makes it difficult for hydroxide groups(-OH)to survive on the surface but also allows the in situ surface reconstruction to generate the ultra-stable MoS_(2)-Mo_(3)Ni_(3)N heterostructures after the initial cycling stage.These can effectively prevent the occurrence of OH-induced LPSC decomposition reaction from producing harmful insulating sulfates,as well as simultaneously constructing the highly-efficient electrons/ions dual-migration pathways at the cathode interfaces to facilitate the improvement of both electrons and Li+ions conductivities in ASSLBs.With this approach,fine-tuned Mo-Ni@NPCs can deliver extremely outstanding performance,including an ultra-high first discharge-specific capacity of 148.61 mAh g^(-1)(0.1C),a high Coulombic efficiency(94.01%),and a capacity retention rate after 1000 cycles still attain as high as 90.62%.This work provides a brand-new approach of“conversionprotection”strategy to overcome the drawbacks of composite cathodes interfaces instability and further promotes the commercialization of ASSLBs.展开更多
Multifunctional additives are widely used to improve crystallization and to passivate defects in perovskite solar cells. The roles of these additives are usually related to the various functional groups contained in s...Multifunctional additives are widely used to improve crystallization and to passivate defects in perovskite solar cells. The roles of these additives are usually related to the various functional groups contained in such additives. Here, we introduce a serious of analogues of amino acids into methylammonium lead iodide perovskites and find they play different roles in the crystallization process despite the fact that these additives share exactly the same terminal groups, namely one amino group and one carboxyl group. The corresponding crystallization pathways are established for the first time via monitoring the time-resolved phase formation and transformation. We find that avoiding the rapid formation of perovskites from precursor solution can facilitate the uniform nucleation and growth of perovskite crystals with enhanced crystallinity and reduced defects. Further, we find the different crystallization behaviors probably arise from the inherent structural characteristic of these additives, leading to different interactions in the precursors. This study unveils the effects of amino acids on the liquid–solid crystallization process and helps better understand the role of multifunctional additives beyond their functional groups.展开更多
Wide-bandgap(WBG)perovskites have been attracting much attention because of their immense potential as a front light-absorber for tandem solar cells.However,WBG perovskite solar cells(PSCs)generally exhibit undesired ...Wide-bandgap(WBG)perovskites have been attracting much attention because of their immense potential as a front light-absorber for tandem solar cells.However,WBG perovskite solar cells(PSCs)generally exhibit undesired large open-circuit voltage(VOC)loss due to light-induced phase segregation and severe non-radiative recombination loss.Herein,antimony potassium tartrate(APTA)is added to perovskite precursor as a multifunctional additive that not only coordinates with unbonded lead but also inhibits the migration of halogen in perovskite,which results in suppressed non-radiative recombination,inhibited phase segregation and better band energy alignment.Therefore,a APTA auxiliary WBG PSC with a champion photoelectric conversion efficiency of 20.35%and less hysteresis is presented.They maintain 80%of their initial efficiencies under 100 mW cm^(-2)white light illumination in nitrogen after 1,000 h.Furthermore,by combining a semi-transparent WBG perovskite front cell with a narrow-bandgap tin–lead PSC,a perovskite/perovskite four-terminal tandem solar cell with an efficiency over 26%is achieved.Our work provides a feasible approach for the fabrication of efficient tandem solar cells.展开更多
基金supported by the National Natural Science Foundation of China (51773134)the Sichuan Science and Technology Program (2019YFH0112)+2 种基金the Fundamental Research Funds for the Central UniversitiesInstitutional Research Fund from Sichuan University (2021SCUNL201)the 111 Project (B20001)。
文摘The rapid development and widespread application of lithium-ion batteries(LIBs) have increased demand for high-safety and high-performance LIBs. Accordingly, various additives have been used in commercial liquid electrolytes to severally adjust the solvation structure of lithium ions, control the components of solid electrolyte interphase, or reduce flammability. While it is highly desirable to develop low-cost multifunctional electrolyte additives integrally that address both safety and performance on LIBs, significant challenges remain. Herein, a novel phosphorus-containing organic small molecule, bis(2-methoxyethyl) methylphosphonate(BMOP), was rationally designed to serve as a fluorine-free and multifunctional additive in commercial electrolytes. This novel electrolyte additive is low-toxicity,high-efficiency, low-cost, and electrode-compatible, which shows the significant improvement to both electrochemical performance and fire safety for LIBs through regulating the electrolyte solvation structure, constructing the stable electrode-electrolyte interphase, and suppressing the electrolyte combustion. This work provides a new avenue for developing safer and high-performance LIBs.
基金support provided by the National Natural Science Foundation of China(Grant No.21804008,52102209)the International Technological Collaboration Project of Shanghai(Grant No.17520710300).
文摘The electrochemical performance of all-solid-state lithium batteries(ASSLBs)can be prominently enhanced by minimizing the detrimental degradation of solid electrolytes through their undesirable side reactions with the conductive carbon additives(CCAs)inside the composite cathodes.Herein,the well-defined Mo_(3)Ni_(3)N nanosheets embedded onto the N-doped porous carbons(NPCs)substrate are successfully synthesized(Mo-Ni@NPCs)as CCAs inside LiCoO_(2)for Li_(6)PSC_5)Cl(LPSCl)-based ASSLBs.This nano-composite not only makes it difficult for hydroxide groups(-OH)to survive on the surface but also allows the in situ surface reconstruction to generate the ultra-stable MoS_(2)-Mo_(3)Ni_(3)N heterostructures after the initial cycling stage.These can effectively prevent the occurrence of OH-induced LPSC decomposition reaction from producing harmful insulating sulfates,as well as simultaneously constructing the highly-efficient electrons/ions dual-migration pathways at the cathode interfaces to facilitate the improvement of both electrons and Li+ions conductivities in ASSLBs.With this approach,fine-tuned Mo-Ni@NPCs can deliver extremely outstanding performance,including an ultra-high first discharge-specific capacity of 148.61 mAh g^(-1)(0.1C),a high Coulombic efficiency(94.01%),and a capacity retention rate after 1000 cycles still attain as high as 90.62%.This work provides a brand-new approach of“conversionprotection”strategy to overcome the drawbacks of composite cathodes interfaces instability and further promotes the commercialization of ASSLBs.
基金financial support from the National Natural Science Foundation of China (Grant No. 22075094, 12075303 and 11675252)the National Key Research and Development Program of China (Grant No. 2016YFA0201101)the Fundamental Research Funds for the Central Universities。
文摘Multifunctional additives are widely used to improve crystallization and to passivate defects in perovskite solar cells. The roles of these additives are usually related to the various functional groups contained in such additives. Here, we introduce a serious of analogues of amino acids into methylammonium lead iodide perovskites and find they play different roles in the crystallization process despite the fact that these additives share exactly the same terminal groups, namely one amino group and one carboxyl group. The corresponding crystallization pathways are established for the first time via monitoring the time-resolved phase formation and transformation. We find that avoiding the rapid formation of perovskites from precursor solution can facilitate the uniform nucleation and growth of perovskite crystals with enhanced crystallinity and reduced defects. Further, we find the different crystallization behaviors probably arise from the inherent structural characteristic of these additives, leading to different interactions in the precursors. This study unveils the effects of amino acids on the liquid–solid crystallization process and helps better understand the role of multifunctional additives beyond their functional groups.
基金supported by the National High Technology Research and Development Program(2015AA050601)the National Natural Science Foundation of China(61904126,12134010,12174290)。
文摘Wide-bandgap(WBG)perovskites have been attracting much attention because of their immense potential as a front light-absorber for tandem solar cells.However,WBG perovskite solar cells(PSCs)generally exhibit undesired large open-circuit voltage(VOC)loss due to light-induced phase segregation and severe non-radiative recombination loss.Herein,antimony potassium tartrate(APTA)is added to perovskite precursor as a multifunctional additive that not only coordinates with unbonded lead but also inhibits the migration of halogen in perovskite,which results in suppressed non-radiative recombination,inhibited phase segregation and better band energy alignment.Therefore,a APTA auxiliary WBG PSC with a champion photoelectric conversion efficiency of 20.35%and less hysteresis is presented.They maintain 80%of their initial efficiencies under 100 mW cm^(-2)white light illumination in nitrogen after 1,000 h.Furthermore,by combining a semi-transparent WBG perovskite front cell with a narrow-bandgap tin–lead PSC,a perovskite/perovskite four-terminal tandem solar cell with an efficiency over 26%is achieved.Our work provides a feasible approach for the fabrication of efficient tandem solar cells.
