Charge carriers in organic semiconductor are different from that of traditional inorganic semiconductor. Based on three-current model, considering electrical field effect, we present a theoretical model to discuss spi...Charge carriers in organic semiconductor are different from that of traditional inorganic semiconductor. Based on three-current model, considering electrical field effect, we present a theoretical model to discuss spin-polarized injection from ferromagnetic electrode into organic semiconductor by analyzing electrochemical potential both in ferromagnetic electrode and organic semiconductors. The calculated result of this model shows effects of electrode＇s spin polarization, equilibrium value of polarons ratio, interracial conductance, bulk conductivity of materials and electrical field. It is found that we could get decent spin polarization with common ferromagnetic electrode by increasing equilibrium value of polarons ratio. We also find that large and matched bulk conductivity of organic semiconductor and electrode, small spin-dependent interracial conductance, and enough large electrical field are critical factors for increasing spin polarization.展开更多
In this work, a rational design and construction of porous spherical Ni O@NiMoO4 wrapped with PPy was reported for the application of high-performance supercapacitor(SC). The results show that the NiMoO4 modification ...In this work, a rational design and construction of porous spherical Ni O@NiMoO4 wrapped with PPy was reported for the application of high-performance supercapacitor(SC). The results show that the NiMoO4 modification changes the morphology of Ni O, and the hollow internal morphology combined with porous outer shell of Ni O@NiMoO4 and Ni O@NiMoO4@PPy hybrids shows an increased specific surface area(SSA), and then promotes the transfer of ions and electrons. The shell of NiMoO4 and PPy with high electronic conductivity decreases the charge-transfer reaction resistance of Ni O, and then improves the electrochemical kinetics of Ni O. At 20 Ag^-1, the initial capacitances of Ni O, NiMoO4, Ni O@NiMoO4 and Ni O@NiMoO4@PPy are 456.0, 803.2, 764.4 and 941.6 Fg^-1, respectively. After 10,000 cycles, the corresponding capacitances are 346.8, 510.8, 641.2 and 904.8 Fg^-1, respectively. Especially, the initial capacitance of Ni O@NiMoO4@PPy is 850.2 Fg^-1, and remains 655.2 Fg^-1 with a high retention of 77.1% at30 Ag^-1 even after 30,000 cycles. The calculation result based on density function theory shows that the much stronger Mo-O bonds are crucial for stabilizing the Ni O@NiMoO4 composite, resulting in a good cycling stability of these materials.展开更多
With the proliferation of energy storage and power applications, electric vehicles particularly, solid-state batteries are considered as one of the most promising strategies to address the ever-increasing safety conce...With the proliferation of energy storage and power applications, electric vehicles particularly, solid-state batteries are considered as one of the most promising strategies to address the ever-increasing safety concern and high energy demand of power devices. Here, we demonstrate the Al4B2O9 nanorods-modified poly(ethylene oxide) (PEO)-based solid polymer electrolyte (ASPE) with high ionic conductivity, wide electrochemical window, decent mechanical property and nonflammable performance. Specifically, because of the longer-range ordered Li+ transfer channels conducted by the interaction between Al4B2O9 nanorods and PEO, the optimal ASPE (ASPE-1) shows excellent ionic conductivity of 4.35×10^−1 and 3.1×10^−1 S cm^−1 at 30 and 60℃, respectively. It also has good electrochemical stability at 60℃ with a decomposition voltage of 5.1 V. Besides, the assembled LiFePO4//Li cells show good cycling performance, delivering 155 mA h g−1 after 300 cycles at 1 C under 60℃, and present excellent low temperature adaptability, retaining over 125 mA h g^−1 after 90 cycles at 0.2 C under 30℃. These results verify that the addition of Al4B2O9 nanorods can effectively promote the integrated performance of solid polymer electrolyte.展开更多
Lithium-rich layered oxide(LLO)cathode materials have drawn extensive attention due to their ultrahigh specific capacity and energy density.However,their commercialization is still restricted by their low initial coul...Lithium-rich layered oxide(LLO)cathode materials have drawn extensive attention due to their ultrahigh specific capacity and energy density.However,their commercialization is still restricted by their low initial coulombic efficiency,slow intrinsic kinetics and structural instability.Herein,a facile surface treatment strategy via gaseous phosphine was designed to improve the rate performance and capacity stability of LLOs.During the solid-gas reaction,phosphine reacted with active oxygen at the surface of LLOs due to its reductivity,forming oxygen vacancies and spinel phase at the surface region.As a result,Li ion conductivity and structural stability were greatly enhanced.The phosphinetreated LLOs(LLO@P)showed a layered-spinel hybrid structure and delivered an outstanding rate performance of156.7 mA h g^-1 at 10 C and a high capacity retention of 74%after 300 cycles at 5 C.展开更多
Hydrogel systems promote the development of flexible energy storage devices because of their inherent mechanical elasticity and ionic conductivity.However,achieving stable energy storage capacity under violent mechani...Hydrogel systems promote the development of flexible energy storage devices because of their inherent mechanical elasticity and ionic conductivity.However,achieving stable energy storage capacity under violent mechanical deformation is still a challenge for hydrogel devices.In this work,an all-in-one integrated supercapacitor(AISC)was assembled using in situ deposited polyaniline/graphene oxide nanocomposites for both sides of the incorporated ionic hydrogel electrolyte.The assembly process of the AISC was greatly simplified,and the displacement and separation of the multilayer structured hydrogel complex were avoided during mechanical deformation.The hydrogel electrolyte with ionic additives exhibited strong adhesion and flexibility,and high ionic conductivity,thereby ensuring the excellent specific capacitance and rate performance of the AISC.The specific capacitances of the AISC were 222.8 mF cm^(−2) at the current density of 0.2 mA cm^(−2) and 151.7 mF cm^(−2) at 3.2 mA cm^(−2).The capacitance retention rate was 68.1%.The energy density of a piece of the device reached 44.6μW h cm^(−2) at a power density of 120.0μW cm^(−2).Moreover,reliable and reproducible energy storage was acquired under bending,compression,and stretching deformations.The AISC was also easily assembled in series to power a light-emitting diode(LED)light.This work provides a facile approach to the construction of flexible supercapacitors for the development of energy storage devices in flexible electronics.展开更多
基金Supported by the Natural Science Foundation of Shandong Province under Grant No.Y2006A18 the Key Programme of Nature Foundation of Shandong Jianzhu University under Grant No.XZ050102
文摘Charge carriers in organic semiconductor are different from that of traditional inorganic semiconductor. Based on three-current model, considering electrical field effect, we present a theoretical model to discuss spin-polarized injection from ferromagnetic electrode into organic semiconductor by analyzing electrochemical potential both in ferromagnetic electrode and organic semiconductors. The calculated result of this model shows effects of electrode＇s spin polarization, equilibrium value of polarons ratio, interracial conductance, bulk conductivity of materials and electrical field. It is found that we could get decent spin polarization with common ferromagnetic electrode by increasing equilibrium value of polarons ratio. We also find that large and matched bulk conductivity of organic semiconductor and electrode, small spin-dependent interracial conductance, and enough large electrical field are critical factors for increasing spin polarization.
基金This work was supported by the National Natural Science Foundation of China(U1960107,21773060,51771046,and 51674068)the Fundamental Research Funds for the Central Universities(N182304014)Key Program for International S&T Cooperation Projects of China(2017YFE0124300).
文摘In this work, a rational design and construction of porous spherical Ni O@NiMoO4 wrapped with PPy was reported for the application of high-performance supercapacitor(SC). The results show that the NiMoO4 modification changes the morphology of Ni O, and the hollow internal morphology combined with porous outer shell of Ni O@NiMoO4 and Ni O@NiMoO4@PPy hybrids shows an increased specific surface area(SSA), and then promotes the transfer of ions and electrons. The shell of NiMoO4 and PPy with high electronic conductivity decreases the charge-transfer reaction resistance of Ni O, and then improves the electrochemical kinetics of Ni O. At 20 Ag^-1, the initial capacitances of Ni O, NiMoO4, Ni O@NiMoO4 and Ni O@NiMoO4@PPy are 456.0, 803.2, 764.4 and 941.6 Fg^-1, respectively. After 10,000 cycles, the corresponding capacitances are 346.8, 510.8, 641.2 and 904.8 Fg^-1, respectively. Especially, the initial capacitance of Ni O@NiMoO4@PPy is 850.2 Fg^-1, and remains 655.2 Fg^-1 with a high retention of 77.1% at30 Ag^-1 even after 30,000 cycles. The calculation result based on density function theory shows that the much stronger Mo-O bonds are crucial for stabilizing the Ni O@NiMoO4 composite, resulting in a good cycling stability of these materials.
基金financially supported by the National Natural Science Foundation of China (51804344)the Huxiang Youth Talent Support Program (2019RS2002)+2 种基金the Innovation and Entrepreneurship Project of Hunan Province,China (2018GK5026)the Innovation-Driven Project of Central South University (2020CX027)Guangdong Yang Fan Plan for Postdoctor Program
文摘With the proliferation of energy storage and power applications, electric vehicles particularly, solid-state batteries are considered as one of the most promising strategies to address the ever-increasing safety concern and high energy demand of power devices. Here, we demonstrate the Al4B2O9 nanorods-modified poly(ethylene oxide) (PEO)-based solid polymer electrolyte (ASPE) with high ionic conductivity, wide electrochemical window, decent mechanical property and nonflammable performance. Specifically, because of the longer-range ordered Li+ transfer channels conducted by the interaction between Al4B2O9 nanorods and PEO, the optimal ASPE (ASPE-1) shows excellent ionic conductivity of 4.35×10^−1 and 3.1×10^−1 S cm^−1 at 30 and 60℃, respectively. It also has good electrochemical stability at 60℃ with a decomposition voltage of 5.1 V. Besides, the assembled LiFePO4//Li cells show good cycling performance, delivering 155 mA h g−1 after 300 cycles at 1 C under 60℃, and present excellent low temperature adaptability, retaining over 125 mA h g^−1 after 90 cycles at 0.2 C under 30℃. These results verify that the addition of Al4B2O9 nanorods can effectively promote the integrated performance of solid polymer electrolyte.
基金financial support from the Ministry of Science and Technology of China(MoST,2016YFA0200200)the National Natural Science Foundation of China(NSFC,21421001 and 51633002)+1 种基金Tianjin city(16ZXCLGX00100)111 Project(B12015)。
文摘Lithium-rich layered oxide(LLO)cathode materials have drawn extensive attention due to their ultrahigh specific capacity and energy density.However,their commercialization is still restricted by their low initial coulombic efficiency,slow intrinsic kinetics and structural instability.Herein,a facile surface treatment strategy via gaseous phosphine was designed to improve the rate performance and capacity stability of LLOs.During the solid-gas reaction,phosphine reacted with active oxygen at the surface of LLOs due to its reductivity,forming oxygen vacancies and spinel phase at the surface region.As a result,Li ion conductivity and structural stability were greatly enhanced.The phosphinetreated LLOs(LLO@P)showed a layered-spinel hybrid structure and delivered an outstanding rate performance of156.7 mA h g^-1 at 10 C and a high capacity retention of 74%after 300 cycles at 5 C.
基金supported by the Natural Science Foundation of Shandong Province(ZR2020KB018)the Natural Science Foundation of Jiangsu Province(BK20190688)+2 种基金the Six Talent Peak Innovation Team in Jiangsu Province(TD-SWYY-009)the"Taishan Scholars"Construction Special Fund of Shandong Provincethe Industrial Alliance Fund of Shandong Provincial Key Laboratory(SDKL2016038)。
文摘Hydrogel systems promote the development of flexible energy storage devices because of their inherent mechanical elasticity and ionic conductivity.However,achieving stable energy storage capacity under violent mechanical deformation is still a challenge for hydrogel devices.In this work,an all-in-one integrated supercapacitor(AISC)was assembled using in situ deposited polyaniline/graphene oxide nanocomposites for both sides of the incorporated ionic hydrogel electrolyte.The assembly process of the AISC was greatly simplified,and the displacement and separation of the multilayer structured hydrogel complex were avoided during mechanical deformation.The hydrogel electrolyte with ionic additives exhibited strong adhesion and flexibility,and high ionic conductivity,thereby ensuring the excellent specific capacitance and rate performance of the AISC.The specific capacitances of the AISC were 222.8 mF cm^(−2) at the current density of 0.2 mA cm^(−2) and 151.7 mF cm^(−2) at 3.2 mA cm^(−2).The capacitance retention rate was 68.1%.The energy density of a piece of the device reached 44.6μW h cm^(−2) at a power density of 120.0μW cm^(−2).Moreover,reliable and reproducible energy storage was acquired under bending,compression,and stretching deformations.The AISC was also easily assembled in series to power a light-emitting diode(LED)light.This work provides a facile approach to the construction of flexible supercapacitors for the development of energy storage devices in flexible electronics.
