Lithium iron phosphate （LiFePO4）/lithium manganese phosphate （LiMnPO4）-positive material was suc- cessfully prepared through ball milling and high-temperature sintering using manganese acetate, lithium hydroxide, ...Lithium iron phosphate （LiFePO4）/lithium manganese phosphate （LiMnPO4）-positive material was suc- cessfully prepared through ball milling and high-temperature sintering using manganese acetate, lithium hydroxide, ammonium dihydrogen phosphate, and ferrous oxalate as raw materials. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, scanning elec- tron microscopy, a constant current charge-discharge test, cyclic voltammetry, and electrochemical impedance spectroscopy. The effects of lithium iron phosphate coating were also discussed. Because of its special core-shell structure, the as-prepared LiMn0.TFe0.3PO4-LiFeP04-C exhibits excellent electro- chemical performance. The discharge capacity reached 136.6 mAh/g and the specific discharge energy reached 506.9 Wh/kg at a rate of 0.1 C.展开更多
In the present paper, multi-walled carbon nanotubes（MWCNTs） are successfully assembled on graphite felt（GF） using sucrose pyrolysis method for the first time. The in situ formed pyrolytic carbon is chosen as the b...In the present paper, multi-walled carbon nanotubes（MWCNTs） are successfully assembled on graphite felt（GF） using sucrose pyrolysis method for the first time. The in situ formed pyrolytic carbon is chosen as the binder because it is essentially carbon materials as well as CNTs and GF which has a natural tendency to achieve high bonding strength and low contact resistance. The MWCNTs/GF electrode is demonstrated to increase surface area, reduce polarization, lower charge transfer resistance and improve energy conversion efficiency comparing with GF. This excellent electrochemical performance is mainly ascribed to the high electro-catalytic activity of MWCNTs and increasing surface area.展开更多
Two types of spinel cathode powders, LiMn2O4 and LiAl0.1Mn1.9O3.9F0.1, were synthesized by solid-state reaction, X-ray diffraction （XRD） patterns of the prepared samples were identified as the spinel structure with ...Two types of spinel cathode powders, LiMn2O4 and LiAl0.1Mn1.9O3.9F0.1, were synthesized by solid-state reaction, X-ray diffraction （XRD） patterns of the prepared samples were identified as the spinel structure with a space group of Fd 3^- m. The cubic lattice parameter was determined from least-squares fitting of the XRD data. The LiAl0.1Mn1.9O3.9F0.1 sample showed a little lower initial capacity, but better cycling performance than the LiMn2O4 sample at both room temperature and an elevated temperature. The Vanderbilt method was used to test the electrochemical conductivity of the LiMn2O4 samples. The electrochemical impedance spectroscopy （EIS） method was employed to investigate the electrochemical properties of these spinel LiMn2O4 samples.展开更多
A new type lead paste mixed with binders used in thin-plate, spirally wound lead acid batteries is introduced. The utility of positive active material can obtain 54.17% and 37.71% at discharge currents of 0.5C and 5.0...A new type lead paste mixed with binders used in thin-plate, spirally wound lead acid batteries is introduced. The utility of positive active material can obtain 54.17% and 37.71% at discharge currents of 0.5C and 5.0C. The investigation was performed by means of X-ray diffraction （XRD）, scaning electron microscopy （SEM）, infrared spectroscopy （IR）, cylic voltammetry （CV）, the results revealed more details on the reaction mechanism of paste-mixing. Further conclusion can be obtained that the reaction of paste-mixin is a physical process, and the chemical reactions is local reaction, which is different from traditional mixing process, the binders has some effect on the formation of battery process. The binders can dissolve in elec trolyte, which have no disadvantageous effect on the charge-discharge performance.展开更多
The aim of this investigation is to define a model of an alternating current impedance response that can identify the state of health of a porous electrode due to the blocked diffusion effect. To identify and simulate...The aim of this investigation is to define a model of an alternating current impedance response that can identify the state of health of a porous electrode due to the blocked diffusion effect. To identify and simulate different pore geometries, an analytical differential equations system was studied. Standard and low performance battery products were simulated by the model and validated with electrochemical impedance spectroscopy （EIS） experimental data. The correlation between pore structure geometries and the related battery efficiency is also addressed. This investigation may clarify the possible reasons for low performance batteries. Identifying the benchmark pore geometry, parameters may be useful for the battery producers to improve the efficiency of their products. Various recovery methods are also included in this investigation to disperse the build-up of lead sulphate crystal that limits the electrolysis process in the low performance batteries.展开更多
基金Financial support from the Knowledge Innovation Program of the Chinese Academy of Sciences （Grant No. KGCX2-YW-341） and the National Natural Science Foundation of China （Grant Nos. 21376247, 21573240） is gratefully acknowledged.
文摘Lithium iron phosphate （LiFePO4）/lithium manganese phosphate （LiMnPO4）-positive material was suc- cessfully prepared through ball milling and high-temperature sintering using manganese acetate, lithium hydroxide, ammonium dihydrogen phosphate, and ferrous oxalate as raw materials. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, scanning elec- tron microscopy, a constant current charge-discharge test, cyclic voltammetry, and electrochemical impedance spectroscopy. The effects of lithium iron phosphate coating were also discussed. Because of its special core-shell structure, the as-prepared LiMn0.TFe0.3PO4-LiFeP04-C exhibits excellent electro- chemical performance. The discharge capacity reached 136.6 mAh/g and the specific discharge energy reached 506.9 Wh/kg at a rate of 0.1 C.
基金financial support of the National Natural Science Foundation of China (project no. 51504231, 51504232, 51774262 and 21325628)Open Project of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization (project no. CNMRCUKF1704)
文摘In the present paper, multi-walled carbon nanotubes（MWCNTs） are successfully assembled on graphite felt（GF） using sucrose pyrolysis method for the first time. The in situ formed pyrolytic carbon is chosen as the binder because it is essentially carbon materials as well as CNTs and GF which has a natural tendency to achieve high bonding strength and low contact resistance. The MWCNTs/GF electrode is demonstrated to increase surface area, reduce polarization, lower charge transfer resistance and improve energy conversion efficiency comparing with GF. This excellent electrochemical performance is mainly ascribed to the high electro-catalytic activity of MWCNTs and increasing surface area.
基金This work was financially supported by the National Natural Science Foundation of China (No.50272012).
文摘Two types of spinel cathode powders, LiMn2O4 and LiAl0.1Mn1.9O3.9F0.1, were synthesized by solid-state reaction, X-ray diffraction （XRD） patterns of the prepared samples were identified as the spinel structure with a space group of Fd 3^- m. The cubic lattice parameter was determined from least-squares fitting of the XRD data. The LiAl0.1Mn1.9O3.9F0.1 sample showed a little lower initial capacity, but better cycling performance than the LiMn2O4 sample at both room temperature and an elevated temperature. The Vanderbilt method was used to test the electrochemical conductivity of the LiMn2O4 samples. The electrochemical impedance spectroscopy （EIS） method was employed to investigate the electrochemical properties of these spinel LiMn2O4 samples.
文摘A new type lead paste mixed with binders used in thin-plate, spirally wound lead acid batteries is introduced. The utility of positive active material can obtain 54.17% and 37.71% at discharge currents of 0.5C and 5.0C. The investigation was performed by means of X-ray diffraction （XRD）, scaning electron microscopy （SEM）, infrared spectroscopy （IR）, cylic voltammetry （CV）, the results revealed more details on the reaction mechanism of paste-mixing. Further conclusion can be obtained that the reaction of paste-mixin is a physical process, and the chemical reactions is local reaction, which is different from traditional mixing process, the binders has some effect on the formation of battery process. The binders can dissolve in elec trolyte, which have no disadvantageous effect on the charge-discharge performance.
基金the financial support from the Knowledge Economy Skills Scholarships (KESS)Yuasa Battery Ltdthe University of South Wales (USW) during this research project
文摘The aim of this investigation is to define a model of an alternating current impedance response that can identify the state of health of a porous electrode due to the blocked diffusion effect. To identify and simulate different pore geometries, an analytical differential equations system was studied. Standard and low performance battery products were simulated by the model and validated with electrochemical impedance spectroscopy （EIS） experimental data. The correlation between pore structure geometries and the related battery efficiency is also addressed. This investigation may clarify the possible reasons for low performance batteries. Identifying the benchmark pore geometry, parameters may be useful for the battery producers to improve the efficiency of their products. Various recovery methods are also included in this investigation to disperse the build-up of lead sulphate crystal that limits the electrolysis process in the low performance batteries.
