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Structural stability of aluminum stabilized alpha nickel hydroxide as a positive electrode material for alkaline secondary batteries
06 Electrical power supply and utilization (scientific, technical) natural gas reduces carbon dioxide by 47.2%, and natural gas reforming and incineration of synthesis gas reduces carbon dioxide by 45.3%. It is possible to remove the formed carbon dioxide from the flue gases, compress it and then utilize it.
dependent on stoichiometry. In the present work, Sn0r.9s is the optimum stoichiometry, exhibiting the highest reversible capacity (498.33 PA h/cm2 pm) and the lowest irreversible capacity (301.79 PA h/cm2 pm).
00100339 Safety studies on lithium-ion batteries by accelerating rate calorimetry
00100344 Structural and electrochemical studies on lithium manganese oxide containing Li’ prepared by hydrothermal method for lithium ion batteries
Lampe-Onnerud, C. et al. Annu. Battery Conf. Appl. Adv., 1999, , 215220. Edited by Frank H.A., Seo E.T. Exothermic reactions of lithium-ion cells at various states of charge have been studied by the accelerating rate calorimetry technique. The thermal stability of a cell is highly dependent on its charged state. The fully discharged cell (discharged to 2.7 V) has the highest thermal stability with the onset temperature of thermal runaway of 120” and the overcharged cell (charged to 4.8 V) has the least thermal stability, starting thermal runaway reaction at 40”.
00100340 Self-discharge of carbon-based supercapacitors with organic electrolytes Ricketts, B. W. and Ton-That, C. J. Partner Sources, 2000, 89, (I), 6469. The self-discharge behaviour of supercapacitors is an important factor when considering their suitability for some applications. In this paper, measurements of the self-discharee rates of carbon-based suoercapacitors with organic electrolytesYare presented and interpreted in terms of two mechanisms. The first is the diffusion of ions from regions of excess ionic concentration formed during the charging of the capacitor and the second is leakage of charge across the double-layer at the electrolyte-carbon interfaces in the capacitor. The dependence of the self-discharge rate on temperature and on the initial voltage across the capacitor is described.
00100341 Solid-state microbatteries for electronics in the 21st century Balkanski, M. Sol. Energy Mat. & Sol. Cells, 2000, 62, (I-2) 21-35. A solid-state battery is an energy converter, transforming chemical into electrical energy by means of internal electron exchange. The electron transfer is mediated by mobile ions released from an ion source, the anode and neutralized in the electron exchanger, the cathode. The positive ion is transmitted through a fast ion conductor, which is a good electronic insulator, the separator. The ideal solid-state battery should be based on one unique material in which three regions corresponding to the ion source, the separator and the electron exchanger are subdivided by internal homojunctions. In addition, suggestions for the optimization of cathode microstructures are presented. 00/00342 Status of Danish solid oxide fuel cell R&D Bagger, C. er al. Proc. - Elecrrochem. Sot., 1999, 99, 28-35. The Danish solid oxide fuel cell program is reviewed. It was established to develop materials, structures and process knowledge with parallel implementation into design, modelling and fabrication technologies. This paper mentions the main achievements of the program, with emphasis on recent results with ceramic interconnect and electrodes for operation at 750-850”. A thin anode supported cell of mainly saturated materials, with thin electrolyte and high handling strength was developed recently using cost effective fabrication techniques suited for scale-up. Area specific resistances are approximately 0.4 wcm’ at 850” and 0.8 wcm* at 750” and remedies for further improvement have been identified. Redox stable anode current collectors and durability issues with special interest in the ageing mechanisms with high current densities and reproducibility in fabrication, are the main projects for future development. A new development program will investigate the possibilities of syngas production from simultaneous electrolysis of steam and carbon dioxide with the primary aim of allowing renewable energy to be stored.
W/O0343 Stoichiometry dependence of electrochemical performance of thin-film SnO, microbattery anodes deposited by radio frequency magnetron sputtering Lee, W. H. et al. J. Power Sources, 2000, 89, (I), 102-105. Thin-film SnO. microbattery anodes, with various oxygen deficiencies, are deposited from a SnOz target on to an ambient temperature substrate by radio frequency (RF) magnetron sputtering. The high reversible capacity and cycle performance characteristics of SnO, are described. RF power density and process gas pressure during deposition are fixed at 2.5 W/cm2 and 10 mTorr, respectively. The SnO,, films are characterized by energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Constant-current galvanostatic charge-discharge tests of half cells are also performed. The stoichiometric parameter x increases with the increase in oxygen partial pressure, but decreases when the number of Sn chips placed on the target material in an argon atmosphere are increased. It is observed that SnO, transforms to lithium oxide and metallic Sn after an initial Li intercalation reaction. The charge-discharge performance of the tin oxide films is found to be
Liu, D er al. Dianhuaxue, 1999, 5, (3), 276-280. (In Chinese) Todorokite manganese oxides containing Li+ with laree tunnel structure (sample M5) have been synthesized using hydyothermal methods from natural manganese oxide nanofibres (sample M4). The structure and composition of the samples were characterized and analysed by XRD, ICP, TGA and DTA. Galvanostatic charge/discharge measurements were used to study its electrochemical behaviour as a cathode material for rechargeable lithium ion insertion. XRD results indicate that the sample M4 is mainly composed of Birnessite and Vernadite structure. Although the sample M4 shows a high initial capacity of approximately 150 mAh/g, its performances decrease gradually over 30 cycles. It is found that the materials have highly reversible charge/discharge cycling performances after being converted into Todorokite lithium manganese oxide (sample M5). This sample exhibits a single reduction step centred at about 2.8 V and its discharge capacity maintains about 110 mAh/g after 180 cycles at c.d. of 0.8 mA/ cm2. For the 3 V cathode material of lithium ion batteries the novel lithium manganese oxide with a large tunnel structure can be utilized.
Structural stability of aluminum stabilized alpha nickel hydroxide as a positive electrode material for alkaline secondary batteries
00100345
Dai, J. et al. J. Power Sources, 2000, 89, (l), 40-45. Nanostructured, aluminium-stabilized nickel, hydroxides described as Nir_,AI,(OH)z.(COs)x,z nHz0 (x = 0.05-0.2). which are similar to aNi(OH)2 xHzO in crystal structure are examined as cathode materials for Ni-Cd cells. The structure, morphology and electrochemical performance are investigated. The structural changes and stability of nanophase aluminium-stabilized, alpha nickel hydroxides with different x values analvsed durine cvclina bv means of oowder X-rav diffraction. Compared with j-Ni(OHjz, ihe nanophask, aluminiumstabilized a-Ni(OH)2 with x = 0.15 is highly stable against overcharge.
Studies on a lead-acid cell with electrodeposited lead and lead dioxide electrodes on carbon
00100346
Das, K. and Mondal, A. J. Power Sources, 2000, 89, (1) 112-l 16. Performance characteristics of a lead-acid cell with electrodeposited lead and lead dioxide electrodes on carbon are evaluated in aqueous sulfuric acid at concentrations raneine from 1 to 4 M. The discharee capacity is practically independenr 07 the discharge rate within tie current range studied (ml-15 mA cm-z). The capacity increases with cycling, possibly due to slow attainment of a ‘spongy’ character for the negative electrode active mass. The capacity also increases with the amount of deposition, reaching a more or less limiting value beyond an optimum deposition. Steady-state discharge behaviour, represented by a voltage plateau, shows a nearly Nernstian response, which indicates that the basic electron-transfer processes are quite fast. Experiments involving less than full charge-discharge cycles showed the charging efficiency to pass through a maximum with charging current. 00100347
The dynamic representation of protection
systems Tilmay, M et al. Elec. Power and Energy Sysf., 2000, 22, (7) 487-496. This paper presents a dynamic model of a protection system based on a differential feeder protection along with the primary power system. A commercially available relay is modelled and its functions explained. A general orimarv power svstem model structure that includes a fullv httegrated proteciion system model is discussed. The protection system model contains dynamic models of both the relays and the transducers. A technique will be described for developing an accurate dynamic model of a numerical protection relay using actual microprocessor codes from a commerciallv available relav. Finallv. the oractical application of the analysis under abnormal system conditions is demonstrated. Different faults are applied to the internal and the external regions of the feeder and the response of the relays examined. 00/00346 Three-phase asymmetrical load-flow Strezoski, V. C. Trpezanovski, L. D. Etec. Power and Energy Sysr., 2000, 22, (7), 51 l-520. This paper deals with the three-phase asymmetrical load-flow problem. It presents a solution of this problem in the sequence domain, which is more efficient than standard solutions in both the phase and the sequence domain. It specially copes with the asymmetrical states of unbalanced power systems. The efficiency is achieved by introducing the following basic advancements of the standard asymmetrical loadflow calculations: (1) elimination of phase-shifts from the sequence circuits of three-phase transformers; (2) enhancement of the standard Fuel and Energy Abstracts
January 2001
35
dependent on stoichiometry. In the present work, Sn0r.9s is the optimum stoichiometry, exhibiting the highest reversible capacity (498.33 PA h/cm2 pm) and the lowest irreversible capacity (301.79 PA h/cm2 pm).
00100339 Safety studies on lithium-ion batteries by accelerating rate calorimetry
00100344 Structural and electrochemical studies on lithium manganese oxide containing Li’ prepared by hydrothermal method for lithium ion batteries
Lampe-Onnerud, C. et al. Annu. Battery Conf. Appl. Adv., 1999, , 215220. Edited by Frank H.A., Seo E.T. Exothermic reactions of lithium-ion cells at various states of charge have been studied by the accelerating rate calorimetry technique. The thermal stability of a cell is highly dependent on its charged state. The fully discharged cell (discharged to 2.7 V) has the highest thermal stability with the onset temperature of thermal runaway of 120” and the overcharged cell (charged to 4.8 V) has the least thermal stability, starting thermal runaway reaction at 40”.
00100340 Self-discharge of carbon-based supercapacitors with organic electrolytes Ricketts, B. W. and Ton-That, C. J. Partner Sources, 2000, 89, (I), 6469. The self-discharge behaviour of supercapacitors is an important factor when considering their suitability for some applications. In this paper, measurements of the self-discharee rates of carbon-based suoercapacitors with organic electrolytesYare presented and interpreted in terms of two mechanisms. The first is the diffusion of ions from regions of excess ionic concentration formed during the charging of the capacitor and the second is leakage of charge across the double-layer at the electrolyte-carbon interfaces in the capacitor. The dependence of the self-discharge rate on temperature and on the initial voltage across the capacitor is described.
00100341 Solid-state microbatteries for electronics in the 21st century Balkanski, M. Sol. Energy Mat. & Sol. Cells, 2000, 62, (I-2) 21-35. A solid-state battery is an energy converter, transforming chemical into electrical energy by means of internal electron exchange. The electron transfer is mediated by mobile ions released from an ion source, the anode and neutralized in the electron exchanger, the cathode. The positive ion is transmitted through a fast ion conductor, which is a good electronic insulator, the separator. The ideal solid-state battery should be based on one unique material in which three regions corresponding to the ion source, the separator and the electron exchanger are subdivided by internal homojunctions. In addition, suggestions for the optimization of cathode microstructures are presented. 00/00342 Status of Danish solid oxide fuel cell R&D Bagger, C. er al. Proc. - Elecrrochem. Sot., 1999, 99, 28-35. The Danish solid oxide fuel cell program is reviewed. It was established to develop materials, structures and process knowledge with parallel implementation into design, modelling and fabrication technologies. This paper mentions the main achievements of the program, with emphasis on recent results with ceramic interconnect and electrodes for operation at 750-850”. A thin anode supported cell of mainly saturated materials, with thin electrolyte and high handling strength was developed recently using cost effective fabrication techniques suited for scale-up. Area specific resistances are approximately 0.4 wcm’ at 850” and 0.8 wcm* at 750” and remedies for further improvement have been identified. Redox stable anode current collectors and durability issues with special interest in the ageing mechanisms with high current densities and reproducibility in fabrication, are the main projects for future development. A new development program will investigate the possibilities of syngas production from simultaneous electrolysis of steam and carbon dioxide with the primary aim of allowing renewable energy to be stored.
W/O0343 Stoichiometry dependence of electrochemical performance of thin-film SnO, microbattery anodes deposited by radio frequency magnetron sputtering Lee, W. H. et al. J. Power Sources, 2000, 89, (I), 102-105. Thin-film SnO. microbattery anodes, with various oxygen deficiencies, are deposited from a SnOz target on to an ambient temperature substrate by radio frequency (RF) magnetron sputtering. The high reversible capacity and cycle performance characteristics of SnO, are described. RF power density and process gas pressure during deposition are fixed at 2.5 W/cm2 and 10 mTorr, respectively. The SnO,, films are characterized by energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Constant-current galvanostatic charge-discharge tests of half cells are also performed. The stoichiometric parameter x increases with the increase in oxygen partial pressure, but decreases when the number of Sn chips placed on the target material in an argon atmosphere are increased. It is observed that SnO, transforms to lithium oxide and metallic Sn after an initial Li intercalation reaction. The charge-discharge performance of the tin oxide films is found to be
Liu, D er al. Dianhuaxue, 1999, 5, (3), 276-280. (In Chinese) Todorokite manganese oxides containing Li+ with laree tunnel structure (sample M5) have been synthesized using hydyothermal methods from natural manganese oxide nanofibres (sample M4). The structure and composition of the samples were characterized and analysed by XRD, ICP, TGA and DTA. Galvanostatic charge/discharge measurements were used to study its electrochemical behaviour as a cathode material for rechargeable lithium ion insertion. XRD results indicate that the sample M4 is mainly composed of Birnessite and Vernadite structure. Although the sample M4 shows a high initial capacity of approximately 150 mAh/g, its performances decrease gradually over 30 cycles. It is found that the materials have highly reversible charge/discharge cycling performances after being converted into Todorokite lithium manganese oxide (sample M5). This sample exhibits a single reduction step centred at about 2.8 V and its discharge capacity maintains about 110 mAh/g after 180 cycles at c.d. of 0.8 mA/ cm2. For the 3 V cathode material of lithium ion batteries the novel lithium manganese oxide with a large tunnel structure can be utilized.
Structural stability of aluminum stabilized alpha nickel hydroxide as a positive electrode material for alkaline secondary batteries
00100345
Dai, J. et al. J. Power Sources, 2000, 89, (l), 40-45. Nanostructured, aluminium-stabilized nickel, hydroxides described as Nir_,AI,(OH)z.(COs)x,z nHz0 (x = 0.05-0.2). which are similar to aNi(OH)2 xHzO in crystal structure are examined as cathode materials for Ni-Cd cells. The structure, morphology and electrochemical performance are investigated. The structural changes and stability of nanophase aluminium-stabilized, alpha nickel hydroxides with different x values analvsed durine cvclina bv means of oowder X-rav diffraction. Compared with j-Ni(OHjz, ihe nanophask, aluminiumstabilized a-Ni(OH)2 with x = 0.15 is highly stable against overcharge.
Studies on a lead-acid cell with electrodeposited lead and lead dioxide electrodes on carbon
00100346
Das, K. and Mondal, A. J. Power Sources, 2000, 89, (1) 112-l 16. Performance characteristics of a lead-acid cell with electrodeposited lead and lead dioxide electrodes on carbon are evaluated in aqueous sulfuric acid at concentrations raneine from 1 to 4 M. The discharee capacity is practically independenr 07 the discharge rate within tie current range studied (ml-15 mA cm-z). The capacity increases with cycling, possibly due to slow attainment of a ‘spongy’ character for the negative electrode active mass. The capacity also increases with the amount of deposition, reaching a more or less limiting value beyond an optimum deposition. Steady-state discharge behaviour, represented by a voltage plateau, shows a nearly Nernstian response, which indicates that the basic electron-transfer processes are quite fast. Experiments involving less than full charge-discharge cycles showed the charging efficiency to pass through a maximum with charging current. 00100347
The dynamic representation of protection
systems Tilmay, M et al. Elec. Power and Energy Sysf., 2000, 22, (7) 487-496. This paper presents a dynamic model of a protection system based on a differential feeder protection along with the primary power system. A commercially available relay is modelled and its functions explained. A general orimarv power svstem model structure that includes a fullv httegrated proteciion system model is discussed. The protection system model contains dynamic models of both the relays and the transducers. A technique will be described for developing an accurate dynamic model of a numerical protection relay using actual microprocessor codes from a commerciallv available relav. Finallv. the oractical application of the analysis under abnormal system conditions is demonstrated. Different faults are applied to the internal and the external regions of the feeder and the response of the relays examined. 00/00346 Three-phase asymmetrical load-flow Strezoski, V. C. Trpezanovski, L. D. Etec. Power and Energy Sysr., 2000, 22, (7), 51 l-520. This paper deals with the three-phase asymmetrical load-flow problem. It presents a solution of this problem in the sequence domain, which is more efficient than standard solutions in both the phase and the sequence domain. It specially copes with the asymmetrical states of unbalanced power systems. The efficiency is achieved by introducing the following basic advancements of the standard asymmetrical loadflow calculations: (1) elimination of phase-shifts from the sequence circuits of three-phase transformers; (2) enhancement of the standard Fuel and Energy Abstracts
January 2001
35