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1
Content available Ogniwa litowo-jonowe wysokiej mocy : przegląd materiałów katodowych
Urbanek K.
Wiadomości Chemiczne
|
2018
|
[Z] 72, 5-6
265--278
EN
Due to lack of practical energy sources – ones that are ecological, economic, portable and capable of being regenerated – storage is necessary in modern world for many areas of life to which people became accustomed. Development of many devices requires convenient electric power sources, often providing high currents and voltages, capable of ensuring large amounts of energy in short time. New technologies of lithium-ion cell batteries are a promising solution to this problem – current technologies are frequently inadequate – however they still require massive workloads in research, development, implementation to industry, and then to consumer market. Because of advancement in this area and evergrowing group of people interested in it is imperative to render an overview of the situation and knowledge of this topic. This article presents a review of most intensely studied cathode materials capable of providing high power, viable paths of improvement and short description of most important features of lithium-ion cells along with issues requiring solutions.
2
Content available The influence of electrochemical battery aging process on an electric vehicle’s range
Polak F.
Journal of KONES
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2018
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Vol. 25, No. 1
325--331
EN
This article presents the influence of aging processes of the electric vehicle’s electrochemical battery. The increasing number of hybrid and electric vehicles increases the demand for durable and efficient sources of energy storage for vehicles. The vehicle's declared range is reduced over time. This is due to the aging of the battery that causes loss of its capacity and loss of its power. To minimize this phenomenon, manufacturers use counteracting solutions that include mounting additional cells in the battery that are switched on when the battery controller identifies a particular battery cell’s failure or high degradation. This is due to the deep and shallow discharges of the battery, the number of charge and discharge cycles, and the age and technology of battery packs. AMESim software was used for the simulation of the electric vehicle. The research was based on modelling the range of the vehicle whose cell capacity includes processes related to aging of the battery. An aging cell algorithm causes the capacity to drop and consequently reduces the range of one full charge. By modelling aging processes, it is possible to determine the battery’s probable capacity loss during vehicle use and to estimate how these processes affect the vehicle's range.
3
Content available Verification of LiFePO4 battery mathematic model
Polak F.
Journal of KONES
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2016
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Vol. 23, No. 4
397--402
EN
Article presents verification of LiFePO4 battery simulation model. Verification of battery model was made to assure real parameters of battery cells used for simulation. Simulation model of battery and test stand, similar to the stand used for test on a real battery, was designed in AMESim software. Data of the battery and single cell of battery characteristics were verified to assure true parameters for further tests of power transmission system of the vehicle. For verification theoretical model of the battery, real tests of battery discharging were performed in laboratory. Test stand used for battery discharging was build. Test stand was equipped in water resistor enable to set up various loads of battery. Electrical parameters of battery and battery cell were collected by voltage probes and current clamps and stored in database. Test was performed in similar condition, each time starting with fully loaded battery. Tests ends when battery management system shut down battery main switch. Tests conditions, virtual and real, were performed during similar battery load. Comparing data from unloading tests in laboratory enable to verify data of battery and battery cells designed in AMESim software. Such verification provide reliable model of the used battery. Model of the battery can be used in further simulation test of vehicle, where battery is installed.
4
Content available remote Opracowanie procedury otrzymywania kompozytów LiFePO4-C o wysokiej aktywności elektrochemicznej w ogniwach typu Li-ion
Baster D., Zając W., Molenda J.
Materiały Ceramiczne
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2013
|
T. 65, nr 1
76--80
PL
W pracy przedstawiono opis syntezy nanometrycznego LiFePO4 oraz przygotowania na jego bazie kompozytu z dodatkiem węgla do zastosowania jako materiał katodowy w ogniwach Li-ion. Badano trzy metody wprowadzania dodatku węglowego: rozcieranie w moździerzu, mielenie w młynie oraz pirolizę żywicy nowolakowej. Na bazie otrzymanych kompozytów przygotowano ogniwa elektrochemiczne typu Li|Li+|LixFePO4. Dla tak skonstruowanych ogniw wyznaczono charakterystyki woltamperometryczne, pojemność właściwą materiału katodowego, odwracalność pracy ogniwa oraz stabilność podczas cyklicznego ładowania i rozładowania. W przypadku zastosowania materiału uzyskanego przez rozcieranie w moździerzu uzyskano ogniwa o napięciu ładowania i rozładowania odpowiednio 3,46 V i 3,50 V, pojemności rozładowania 166 mAh•g-1, odwracalności około 98% i stabilnej pracy w ciągu pierwszych dziesięciu cykli ładowania-rozładowania.
EN
This work presents procedures of the nano-sized LiFePO4 synthesis and preparation of LiFePO4-based composite cathode material with carbon addition for Li-ion batteries. Three methods of preparing the LiFePO4-C composite materials were investigated: grinding in an agate mortar, mechanical milling and pyrolysis of novolac resin. The obtained powders were applied as cathode materials in Li|Li+|LixFePO4-type cells. Cyclic voltammetry, specific capacity of the cathode material, reversibility and stability during charge-discharge cycles measurements were carried out to characterize electrochemical properties of the cells. The LiFePO4-C cathode material prepared by grinding in the mortar showed stable voltage of 3.46–3.50 V during charge and discharge cycling. The discharge capacity was about 166 mAh•g-1 with reversibility around 98% and high stability of capacity within the first ten cycles.
5
Content available remote Set up and test of a LiFePO4 battery bank for electric vehicle
Pereirinha P. P., Trovao J., Santiago A.
Przegląd Elektrotechniczny
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2012
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R. 88, nr 1a
193-197
EN
This paper deals with the set up and characterization tests of a lithium iron phosphate, LiFePO4, battery bank for an electric vehicle. he first charge and discharge, a simple system to monitor and ensure tight voltage limits and a LabVIEWŠ system to measure the voltages, currents and calculate the battery pack effective capacity and charge/discharge efficiency are presented. The efficiency and harmonic contents of the used chargers are measured. The installation of a commercial battery management system and its impact in previous results are also discussed.
PL
W artykule przedstawiono testy parametrów banku baterii lithium iron phosphate, LiFePO4 w zastosowaniu do pojazdów elektrycznych. Przedstawiono system do testowania pojemności baterii oraz skuteczności ładowania i rozładowania.
6
Content available remote Chemiczna modyfikacja powierzchni LiFePO4 dla uzyskania materiału katodowego dla ogniw litowych o wysokiej pojemności
Baster D., Zając W., Molenda J.
Czasopismo Techniczne. Mechanika
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2012
|
R. 109, z. 9-M
23--31
PL
W artykule przedstawiono opis syntezy nanometrycznego LiFePO4 oraz metodę chemicznej modyfikacji powierzchni w celu uzyskania materiału katodowego dla ogniw typu Li-ion o wysokiej pojemności. Modyfikacja powierzchni polegała na poddaniu wyjściowego materiału działaniu atmosfery redukcyjnej (mieszanina Ar-H2) w temperaturze 300°C. Przygotowane materiały katodowe użyto do konstrukcji ogniw o schemacie Li/Li+/LixFePO4. Najlepsze uzyskane ogniwa charakteryzowały się pojemnością rozładowania 158 mAh·g-1 w ciągu 10 pierwszych cykli pracy przy odwracalności wynoszącej 0,99.
EN
In this work, we presented a procedure of synthesis of the nano-sized LiFePO4 and method of chemical surface modification in order to obtain cathode material for Li-ion batteries with high discharge capacity. The surface modification of LiFePO4 were performed by annealing in reducing atmosphere (Ar-H2 mixture) at 300°C. The LiFePO4 powders were used as cathode material in Li+/LixFePO4 cells. They exhibited high discharge capacity around 158 mAh·g-1 in first 10 cycles and excellent cyclic ability around 0.99.
7
Content available remote Synteza i właściwości LiFePO4 – materiału katodowego dla ogniw typu Li-ion – otrzymanego metodą niskotemperaturową
Zając W., Rusinek D., Molenda J.
Materiały Ceramiczne
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2011
|
T. 63, nr 2
261-265
PL
W pracy przedstawiono opis syntezy LiFePO4 polegającej na wytrącaniu osadu z roztworu zawierającego LiOH, FeSO4 i H3PO4. Jednofazowy materiał składający się z płytkowych krystalitów o rozmiarach 50 x 500 x 500 nm otrzymano po wysuszeniu uzyskanego osadu w 50°C. Wygrzewanie wyprasek przygotowanych z otrzymanego materiału w temperaturach od 300 do 800°C w atmosferze ochronnej powodowało poprawę krystaliczności materiału, znaczny rozrost krystalitów powyżej 600°C oraz spiekanie powyżej 700°C. Wypraska wygrzewana w 800°C osiągnęła gęstość bliską gęstości teoretycznej. Analiza spieków LiFePO4 metodą dyfrakcji rentgenowskiej wykazała, że podczas wygrzewania powyżej 400°C następuje stopniowy wzrost objętości komórki elementarnej, co prawdopodobnie można powiązać z parowaniem litu połączonym z utworzeniem wakancji kationowych i dziur elektronowych. Analiza przewodnictwa elektrycznego uzyskanych spieków wskazuje, że materiały wygrzewane w temperaturze 700 i 800°C charakteryzują się blisko dwukrotnie wyższym przewodnictwem (9,6•10-6 Sźcm-1) niż materiały wygrzewane w niższej temperaturze (5,5-6,3•10-6 Sźcm-1). Wykazują one również niższe wartości energii aktywacji (0,61-0,66 eV) w porównaniu z próbkami z niższych temperatur (0,76-0,85 eV). Przeprowadzone badania uzupełniono o testy pracy materiału w ogniwach Li/Li+/LixFePO4. Zgodnie z zarejestrowanymi charakterystykami napięcie pracy ogniwa wynosiło między 3,2 a 3,5 V. Pojemność ogniwa w pierwszym cyklu wyniosła około 60 mAhg-1. Następnie w początkowych cyklach obserwowano nieznaczny wzrost pojemności, a następnie stosunkowo szybki spadek aż do około 12 mAhg-1 w pięćdziesiątym cyklu.
EN
In this work, we describe a procedure of synthesis of the LiFePO4 material based on precipitation from a solution containing LiOH, FeSO4 and H3PO4. Single-phased material composed of lamellar crystallites of 50x50x500 nm in size was obtained after drying the precipitated deposit at 50°C. Annealing pellets at temperatures in the range from 300 to 800°C under inert atmosphere led to improvement of crystallinity, intense grain growth (above 600°C), and sintering (above 700°C). For the pellet annealed at 800°C, a density close to theoretical one was achieved. X-ray diffraction revealed that during annealing above 400°C the volume of unit cell gradually increased. Probably this can be connected with evaporation of lithium, which can be associated with the creation of cation vacancies and electron holes. Electrical conductivity measurements showed that LiFePO4 annealed at 700 and 800°C possesses nearly twice as high conductivity (9.6 Sźcm-1) as LiFePO4 annealed at lower temperatures (5.5-6.3 Sźcm-1). At the same time, the materials from higher temperatures were characterised by lower activation energy of electrical conductivity (0.61-0.66 eV) in comparison with the samples from lower temperatures (0.76-0.85 eV). The conducted research was complemented with the charge/discharge tests performed on a Li/Li+/LixFePO4 cell. According to the measured data, the discharge cell voltage was between 3.2 and 3.5 V. The first discharge capacity was about 60 mAhg-1. In the several following cycles, the capacity slightly increased and then gradually decreased to 12 mAhg-1 in the 50th cycle.
8
Content available remote The effect of aluminium on the electrical and electrochemical properties of phospho-olivine - a cathode material for Li-ion batteries
Zając W., Marzec J., Molenda J.
Materials Science Poland
|
2006
|
Vol. 24, No. 1
123--131
EN
The structure, electrical and electrochemical properties of phospho-olivine (LiFePO4) doped with aluminium were investigated. Some of the obtained samples had much higher electrical conductivities than the undoped material (10-4 S/cm compared to 10-10 S/cm). It has been stated that the enhanced conductivity is caused by a thin layer of reduced material that has metallic properties (probably iron phosphide), formed on the grain surfaces of phospho-olivine.
9
Content available remote Lithium-ion batteries - state of art. Novel phospho-olivine cathode materials
Molenda J.
Materials Science Poland
|
2006
|
Vol. 24, No. 1
61--67
EN
This work is a brief review of physicochemical properties of modern cathode materials for Li-ion batteries. These intercalated transition metal compounds of layered, spinel or olivine-type structure exhibit a correlation between their microscopic electronic properties and the efficiency and mechanism of lithium intercalation. The recently reported metallic-type conductivity of doped phospho-olivine LiFePO4, being a novel promising cathode material, is discussed in more detail, and some fundamental arguments are presented against the bulk nature of the observed high electronic conductivi
10
Electronic Aspect of Intercalation in Layered, Spinel and Olivine Type Cathode Materials
Molenda J.
Polish Journal of Chemistry
|
2004
|
Vol. 78 / nr 9
1413-1421
EN
The ability and efficiency of lithium intercalation into transition metal compounds has been found to depend strongly on their electronic structure. This work is a brief review of physicochemical properties of intercalated transition metal compounds with layered, spinel or olivine type structure in order to correlate their microscopic electronic properties i.e. the nature of electronic states with the efficiency of lithium intercalation process which is directed by the chemical diffusion coefficient of lithium. The data concerning cell voltages and character of discharge curves for various materials are correlated with the nature of chemical bonding and electronic structure. The nature of the metallic type conductivity of doped phospho-olivine is discussed and some fundamental arguments against the bulk nature of the observed high electronic conductivity are presented.
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