Hybrid power sources have attracted much attention in the electric vehicle area. Particularly, electric-electric hybrid powertrain system consisting of supercapacitor modules and lithium-ion batteries has been widely ...Hybrid power sources have attracted much attention in the electric vehicle area. Particularly, electric-electric hybrid powertrain system consisting of supercapacitor modules and lithium-ion batteries has been widely applied because of the high power density of supercapacitors. In this study, we design a hybrid powertrain system containing two porous carbon electrode-based supercapacitor modules in parallel and one lithium ion battery pack. With the construction of the testing station, the performance and stability of the used supercapacitor modules are investigated in correlation with the structure of the supercapacitor and the nature of the electrode materials applied. It has been shown that the responding time for voltage vibration from 20 V to 48.5 V during charging or discharging process decreases from about 490 s to 94 s with the increase in applied current from 20 A to 100 A. The capacitance of the capacitor modules is nearly independent on the applied current. With the designed setup, the energy efficiency can reach as high as 0.99. The results described here provide a guidance for material selection of supercapacitors and optimized controlling strategy for hybrid power system applied in electric vehicles.展开更多
LiCoO_(2) is the preferred cathode material for consumer electronic products due to its high volumetric energy density. However, the unfavorable phase transition and surface oxygen release limits the practical applica...LiCoO_(2) is the preferred cathode material for consumer electronic products due to its high volumetric energy density. However, the unfavorable phase transition and surface oxygen release limits the practical application of LiCoO_(2)at a high-voltage of 4.6 V to achieve a higher energy density demanded by the market. Herein, both bulk and surface structures of LiCoO_(2)are stabilized at 4.6 V through oxygen charge regulation by Gd-gradient doping. The enrichment of highly electropositive Gd on LiCoO_(2) surface will increase the effective charge on oxygen and improve the oxygen framework stability against oxygen loss.On the other hand, Gd ions occupy the Co-sites and suppress the unfavorable phase transition and microcrack. The modified LiCoO_(2) exhibits superior cycling stability with capacity retention of 90.1% over 200 cycles at 4.6 V, and also obtains a high capacity of 145.7 m Ah/g at 5 C. This work shows great promise for developing high-voltage LiCoO_(2) at 4.6 V and the strategy could also contribute to optimizing other cathode materials with high voltage and large capacity, such as cobalt-free high-nickel and lithiumrich manganese-based cathode materials.展开更多
采用固含量及pH值、SEM、IR、TGA/DSC等分析方法对两种木素进行理化性能分析。对分别采用这两种木素的12 V 70 Ah样品电池进行低温放电性能、充电接受能力和循环寿命性能验证。结果发现:两种木素在官能团及热重分析的第1个吸热峰存在差...采用固含量及pH值、SEM、IR、TGA/DSC等分析方法对两种木素进行理化性能分析。对分别采用这两种木素的12 V 70 Ah样品电池进行低温放电性能、充电接受能力和循环寿命性能验证。结果发现:两种木素在官能团及热重分析的第1个吸热峰存在差异。木素B对铅酸蓄电池的低温放电性能、25℃下17.5%DoD循环寿命和60℃下17.5%DoD循环寿命更有利。通过综合分析木素B的理化性能和电化学性能得出了木素B的最佳添加量。展开更多
Conducting polyaniline (PANI) powder was well mixed with graphite and acetylene black to obtain the optimum conductivity and porosity. The mixed powder was compressed into a pellet for cathode. Zinc powder was mixed w...Conducting polyaniline (PANI) powder was well mixed with graphite and acetylene black to obtain the optimum conductivity and porosity. The mixed powder was compressed into a pellet for cathode. Zinc powder was mixed with some metal powder, and compressed into a pellet used as the anode. The electrolyte comprised ZnCl2, NH4Cl, Triton-X100 and PVA at pH 3. The battery has an open-circuit voltage of 1.44 V. The battery underwent charge-discharge cycle with a constant current density of 3 mA·cm-2, within the voltage range of 0.40-1.68 V. It is found that the capacity of the battery is related to the charge-discharge cycles, the maximum capacity is 67.9 mAh·g-1, and Coulombic efficiency is between 95% and 100%. The battery stability was also investigated after 78 d of standing without use. It is found that the battery experiences a self-discharge of less than 0.29% per day.展开更多
In Senegal, the Diamniadio, Sebikhotane and Bargny sector contains clay soils that are problematic for construction. In order to have more information on the behavior of the clay soils of Diamniadio, free swelling tes...In Senegal, the Diamniadio, Sebikhotane and Bargny sector contains clay soils that are problematic for construction. In order to have more information on the behavior of the clay soils of Diamniadio, free swelling tests followed by load-discharge cycles were carried out according to standard NF P 94-090-1. These tests were carried out using an Oedometric device on the three samples from the study site (sandy clays with calcareous concretion, marls with crumbs and laminated marls with attapulgite) to apprehend their swelling aspects in saturated conditions. For the free swelling test, a determination of the different swelling phases will be carried out followed by a comparison of the rate of evolution of the phases for the three samples from the site. In the same vein, the compressibility characteristics of the samples will also be provided from load-unload Oedometric tests. Thereafter, we proceed to a comparison of the void index at the initial state of the samples after two charge-discharge cycles and the influence of the cycles on the reorganization of the internal structure of the samples. These studies will provide more information on the swelling behavior of Diamniadio soils in the presence of water.展开更多
基金Funded by the National Key Basic Research Development Program of China(973 Plan)(No.2013CB632505)the National Natural Science Foundation of China(51477125)the Scientific Research Foundation for the Returned Overseas Chinese Scholars
文摘Hybrid power sources have attracted much attention in the electric vehicle area. Particularly, electric-electric hybrid powertrain system consisting of supercapacitor modules and lithium-ion batteries has been widely applied because of the high power density of supercapacitors. In this study, we design a hybrid powertrain system containing two porous carbon electrode-based supercapacitor modules in parallel and one lithium ion battery pack. With the construction of the testing station, the performance and stability of the used supercapacitor modules are investigated in correlation with the structure of the supercapacitor and the nature of the electrode materials applied. It has been shown that the responding time for voltage vibration from 20 V to 48.5 V during charging or discharging process decreases from about 490 s to 94 s with the increase in applied current from 20 A to 100 A. The capacitance of the capacitor modules is nearly independent on the applied current. With the designed setup, the energy efficiency can reach as high as 0.99. The results described here provide a guidance for material selection of supercapacitors and optimized controlling strategy for hybrid power system applied in electric vehicles.
基金supported by the National Natural Science Foundation of China (52102249, 52172201, 51732005, 51902118)the China Postdoctoral Science Foundation (2019M662609 and 2020T130217)+1 种基金the international postdoctoral exchange fellowship program (PC2021026)the Major Technological Innovation Project of Hubei Province (2019AAA019) for financial support。
文摘LiCoO_(2) is the preferred cathode material for consumer electronic products due to its high volumetric energy density. However, the unfavorable phase transition and surface oxygen release limits the practical application of LiCoO_(2)at a high-voltage of 4.6 V to achieve a higher energy density demanded by the market. Herein, both bulk and surface structures of LiCoO_(2)are stabilized at 4.6 V through oxygen charge regulation by Gd-gradient doping. The enrichment of highly electropositive Gd on LiCoO_(2) surface will increase the effective charge on oxygen and improve the oxygen framework stability against oxygen loss.On the other hand, Gd ions occupy the Co-sites and suppress the unfavorable phase transition and microcrack. The modified LiCoO_(2) exhibits superior cycling stability with capacity retention of 90.1% over 200 cycles at 4.6 V, and also obtains a high capacity of 145.7 m Ah/g at 5 C. This work shows great promise for developing high-voltage LiCoO_(2) at 4.6 V and the strategy could also contribute to optimizing other cathode materials with high voltage and large capacity, such as cobalt-free high-nickel and lithiumrich manganese-based cathode materials.
文摘采用固含量及pH值、SEM、IR、TGA/DSC等分析方法对两种木素进行理化性能分析。对分别采用这两种木素的12 V 70 Ah样品电池进行低温放电性能、充电接受能力和循环寿命性能验证。结果发现:两种木素在官能团及热重分析的第1个吸热峰存在差异。木素B对铅酸蓄电池的低温放电性能、25℃下17.5%DoD循环寿命和60℃下17.5%DoD循环寿命更有利。通过综合分析木素B的理化性能和电化学性能得出了木素B的最佳添加量。
基金This work was financially supported by the National Natural Science Foundation of China (No.10374053)
文摘Conducting polyaniline (PANI) powder was well mixed with graphite and acetylene black to obtain the optimum conductivity and porosity. The mixed powder was compressed into a pellet for cathode. Zinc powder was mixed with some metal powder, and compressed into a pellet used as the anode. The electrolyte comprised ZnCl2, NH4Cl, Triton-X100 and PVA at pH 3. The battery has an open-circuit voltage of 1.44 V. The battery underwent charge-discharge cycle with a constant current density of 3 mA·cm-2, within the voltage range of 0.40-1.68 V. It is found that the capacity of the battery is related to the charge-discharge cycles, the maximum capacity is 67.9 mAh·g-1, and Coulombic efficiency is between 95% and 100%. The battery stability was also investigated after 78 d of standing without use. It is found that the battery experiences a self-discharge of less than 0.29% per day.
文摘In Senegal, the Diamniadio, Sebikhotane and Bargny sector contains clay soils that are problematic for construction. In order to have more information on the behavior of the clay soils of Diamniadio, free swelling tests followed by load-discharge cycles were carried out according to standard NF P 94-090-1. These tests were carried out using an Oedometric device on the three samples from the study site (sandy clays with calcareous concretion, marls with crumbs and laminated marls with attapulgite) to apprehend their swelling aspects in saturated conditions. For the free swelling test, a determination of the different swelling phases will be carried out followed by a comparison of the rate of evolution of the phases for the three samples from the site. In the same vein, the compressibility characteristics of the samples will also be provided from load-unload Oedometric tests. Thereafter, we proceed to a comparison of the void index at the initial state of the samples after two charge-discharge cycles and the influence of the cycles on the reorganization of the internal structure of the samples. These studies will provide more information on the swelling behavior of Diamniadio soils in the presence of water.
