采用水热法,以锡酸钠为原料,醋酸锌为锌料,制备出锌掺杂量不同的SnO_2纳米负极材料。电压在0.01~3.0 V,电流密度为100 m A/g的条件下进行电化学测试,结果表明锌掺杂量10%的SnO_2材料首次放电容量可达1895.3 m Ah/g,50次循环后放容量保持...采用水热法,以锡酸钠为原料,醋酸锌为锌料,制备出锌掺杂量不同的SnO_2纳米负极材料。电压在0.01~3.0 V,电流密度为100 m A/g的条件下进行电化学测试,结果表明锌掺杂量10%的SnO_2材料首次放电容量可达1895.3 m Ah/g,50次循环后放容量保持206.1 m Ah/g。因此,锌掺杂量10%的SnO_2材料有较好的电化学性能。展开更多
Current research on vanadium oxides in lithium ion batteries （LIBs） considers them as cathode materials, whereas they are rarely studied for use as anodes in LIBs because of their low electrical conductivity and rap...Current research on vanadium oxides in lithium ion batteries （LIBs） considers them as cathode materials, whereas they are rarely studied for use as anodes in LIBs because of their low electrical conductivity and rapid capacity fading. In this work, hydrogenated vanadium oxide nanoneedles were prepared and incorporated into freeze-dried graphene foam. The hydrogenated vanadium oxides show greatly improved charge-transfer kinetics, which lead to excellent electrochemical properties. When tested as anode materials （0.005-3.0 V vs. Li/Li＋） in LIBs, the sample activated at 600℃ exhibits high specific capacity （-941 mA-h-g-1 at 100 mA.g-1） and high-rate capability （-504 mA·h·g-1 at 5 A·g-1）, as well as excellent cycling performance （-285 mA.h.g-1 in the 1,000th cycle at 5A-g-1）. These results demonstrate the promising application of vanadium oxides as anodes in LIBs.展开更多
To move the performance of lithium-ion batteries into the next stage,the modification of the structure of cells is the only choice except for the development of materials exhibiting higher performance.In this review p...To move the performance of lithium-ion batteries into the next stage,the modification of the structure of cells is the only choice except for the development of materials exhibiting higher performance.In this review paper,the employment of through-holing structures of anodes and cathodes prepared with a picosecond pulsed laser has been proposed.The laser system and the structure for improving the battery performance were introduced.The performance of laminated cells constructed with through-holed anodes and cathodes was reviewed from the viewpoints of the improvement of high-rate performance and energy density,removal of unbalanced capacities on both sides of the current collector,even greater high-rate performance by hybridizing cathode materials and removal of irreversible capacity.In conclusion,the points that should be examined and the problem for the through-holed structure to be in practical use are summarized.展开更多
Lithium-ion batteries are commonly used in electric vehicles,mobile phones,and laptops.These batteries demonstrate several advantages,such as environmental friendliness,high energy density,and long life.However,batter...Lithium-ion batteries are commonly used in electric vehicles,mobile phones,and laptops.These batteries demonstrate several advantages,such as environmental friendliness,high energy density,and long life.However,battery overcharging and overdischarging may occur if the batteries are not monitored continuously.Overcharging causesfire and explosion casualties,and overdischar-ging causes a reduction in the battery capacity and life.In addition,the internal resistance of such batteries varies depending on their external temperature,elec-trolyte,cathode material,and other factors;the capacity of the batteries decreases with temperature.In this study,we develop a method for estimating the state of charge(SOC)using a neural network model that is best suited to the external tem-perature of such batteries based on their characteristics.During our simulation,we acquired data at temperatures of 25°C,30°C,35°C,and 40°C.Based on the tem-perature parameters,the voltage,current,and time parameters were obtained,and six cycles of the parameters based on the temperature were used for the experi-ment.Experimental data to verify the proposed method were obtained through a discharge experiment conducted using a vehicle driving simulator.The experi-mental data were provided as inputs to three types of neural network models:mul-tilayer neural network(MNN),long short-term memory(LSTM),and gated recurrent unit(GRU).The neural network models were trained and optimized for the specific temperatures measured during the experiment,and the SOC was estimated by selecting the most suitable model for each temperature.The experimental results revealed that the mean absolute errors of the MNN,LSTM,and GRU using the proposed method were 2.17%,2.19%,and 2.15%,respec-tively,which are better than those of the conventional method(4.47%,4.60%,and 4.40%).Finally,SOC estimation based on GRU using the proposed method was found to be 2.15%,which was the most accurate.展开更多
锂离子电池在我国电动汽车等领域中被广泛应用,因此,加强其性能的研究具有重要意义。本文通过高浓度水热法合成LiMn_(1/3)Fe_(2/3)PO_(4)/C复合正极材料;利用SEM、X-ray对其进行表征分析;采用首次充放电、循环伏安等方法测试该材料的电...锂离子电池在我国电动汽车等领域中被广泛应用,因此,加强其性能的研究具有重要意义。本文通过高浓度水热法合成LiMn_(1/3)Fe_(2/3)PO_(4)/C复合正极材料;利用SEM、X-ray对其进行表征分析;采用首次充放电、循环伏安等方法测试该材料的电化学性能。制备所得的LiMn_(1/3)Fe_(2/3)PO_(4)/C复合材料在0.1 C时,第1圈的充、放电比容量分别为160.3 mAh g^(-1)、153.3 mAh g^(-1),库伦效率为95.66%;循环47圈后,放电比容量为137.6 mAh g^(-1),容量保持率为89.75%。实验结果表明,该方法制备得到的材料循环稳定性较为优异,使用寿命较长,是较理想的锂离子电池正极材料。展开更多
文摘采用水热法,以锡酸钠为原料,醋酸锌为锌料,制备出锌掺杂量不同的SnO_2纳米负极材料。电压在0.01~3.0 V,电流密度为100 m A/g的条件下进行电化学测试,结果表明锌掺杂量10%的SnO_2材料首次放电容量可达1895.3 m Ah/g,50次循环后放容量保持206.1 m Ah/g。因此,锌掺杂量10%的SnO_2材料有较好的电化学性能。
文摘Current research on vanadium oxides in lithium ion batteries （LIBs） considers them as cathode materials, whereas they are rarely studied for use as anodes in LIBs because of their low electrical conductivity and rapid capacity fading. In this work, hydrogenated vanadium oxide nanoneedles were prepared and incorporated into freeze-dried graphene foam. The hydrogenated vanadium oxides show greatly improved charge-transfer kinetics, which lead to excellent electrochemical properties. When tested as anode materials （0.005-3.0 V vs. Li/Li＋） in LIBs, the sample activated at 600℃ exhibits high specific capacity （-941 mA-h-g-1 at 100 mA.g-1） and high-rate capability （-504 mA·h·g-1 at 5 A·g-1）, as well as excellent cycling performance （-285 mA.h.g-1 in the 1,000th cycle at 5A-g-1）. These results demonstrate the promising application of vanadium oxides as anodes in LIBs.
基金Supported by the National Nature Science Foundation of China (50372003, 50472005)Tsinghua University Fundamental Research Fund (Project No. JC2003040)
文摘To move the performance of lithium-ion batteries into the next stage,the modification of the structure of cells is the only choice except for the development of materials exhibiting higher performance.In this review paper,the employment of through-holing structures of anodes and cathodes prepared with a picosecond pulsed laser has been proposed.The laser system and the structure for improving the battery performance were introduced.The performance of laminated cells constructed with through-holed anodes and cathodes was reviewed from the viewpoints of the improvement of high-rate performance and energy density,removal of unbalanced capacities on both sides of the current collector,even greater high-rate performance by hybridizing cathode materials and removal of irreversible capacity.In conclusion,the points that should be examined and the problem for the through-holed structure to be in practical use are summarized.
基金supported by the BK21 FOUR project funded by the Ministry of Education,Korea(4199990113966).
文摘Lithium-ion batteries are commonly used in electric vehicles,mobile phones,and laptops.These batteries demonstrate several advantages,such as environmental friendliness,high energy density,and long life.However,battery overcharging and overdischarging may occur if the batteries are not monitored continuously.Overcharging causesfire and explosion casualties,and overdischar-ging causes a reduction in the battery capacity and life.In addition,the internal resistance of such batteries varies depending on their external temperature,elec-trolyte,cathode material,and other factors;the capacity of the batteries decreases with temperature.In this study,we develop a method for estimating the state of charge(SOC)using a neural network model that is best suited to the external tem-perature of such batteries based on their characteristics.During our simulation,we acquired data at temperatures of 25°C,30°C,35°C,and 40°C.Based on the tem-perature parameters,the voltage,current,and time parameters were obtained,and six cycles of the parameters based on the temperature were used for the experi-ment.Experimental data to verify the proposed method were obtained through a discharge experiment conducted using a vehicle driving simulator.The experi-mental data were provided as inputs to three types of neural network models:mul-tilayer neural network(MNN),long short-term memory(LSTM),and gated recurrent unit(GRU).The neural network models were trained and optimized for the specific temperatures measured during the experiment,and the SOC was estimated by selecting the most suitable model for each temperature.The experimental results revealed that the mean absolute errors of the MNN,LSTM,and GRU using the proposed method were 2.17%,2.19%,and 2.15%,respec-tively,which are better than those of the conventional method(4.47%,4.60%,and 4.40%).Finally,SOC estimation based on GRU using the proposed method was found to be 2.15%,which was the most accurate.
文摘锂离子电池在我国电动汽车等领域中被广泛应用,因此,加强其性能的研究具有重要意义。本文通过高浓度水热法合成LiMn_(1/3)Fe_(2/3)PO_(4)/C复合正极材料;利用SEM、X-ray对其进行表征分析;采用首次充放电、循环伏安等方法测试该材料的电化学性能。制备所得的LiMn_(1/3)Fe_(2/3)PO_(4)/C复合材料在0.1 C时,第1圈的充、放电比容量分别为160.3 mAh g^(-1)、153.3 mAh g^(-1),库伦效率为95.66%;循环47圈后,放电比容量为137.6 mAh g^(-1),容量保持率为89.75%。实验结果表明,该方法制备得到的材料循环稳定性较为优异,使用寿命较长,是较理想的锂离子电池正极材料。
基金Foundation item：The project supposed by National Natural Science Foundation of China（20376086）Postdoctoral Science Foundation of China（2005037700）Postdoctoral science Foundation of Central South University,China（2004107）
