Lithium iron phosphate based battery: Assessment of the aging parameters and development of cycle life model

A flexible model for economic operational management of grid battery energy storage

Fast charging is attractive to battery electric vehicle (BEV) drivers for its ability to enable long-distance travel and to quickly recharge depleted batteries on short notice. However, such aggressive charging and the sustained vehicle operation that results could lead to excessive battery temperatures and degradation. Properly assessing the consequences of fast charging requires accounting for disparate cycling, heating, and aging of individual cells in large BEV packs when subjected to realistic travel patterns, usage of fast chargers, and climates over long durations (i.e., years). The U.S. Department of Energy's Vehicle Technologies Office has supported the National Renewable Energy Laboratory's development of BLAST-V-the Battery Lifetime Analysis and Simulation Tool for Vehicles-to create a tool capable of accounting for all of these factors. We present on the findings of applying this tool to realistic fast charge scenarios. The effects of different travel patterns, climates, battery sizes, battery thermal management systems, and other factors on battery performance and degradation are presented. We find that the impact of realistic fast charging on battery degradation is minimal for most drivers, due to the low frequency of use. However, in the absence of active battery cooling systems, a driver's desired utilization of a BEV and fast charging infrastructure can result in unsafe peak battery temperatures. We find that active battery cooling systems can control peak battery temperatures to safe limits while allowing the desired use of the vehicle.

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Will Your Battery Survive a World With Fast Chargers

Modelling of degradation and a soft failure moment during the operation of a supercapacitor applying selected diffusion processes

In remote islands, due to expense of existing generation systems, installation of photovoltaic cells (PVs) and wind turbines has a chance of reducing generation costs. However, in island power systems, even short-term power fluctuations change the frequency of grids because of their small inertia constant. In order to compensate power fluctuations, the authors proposed the power consumption control of pumps which send water to tanks. The power control doesn’t affect water users’ convenience as long as tanks hold water. Based on experimental characteristics of a pump system, this paper shows methods to determine reference power consumption of the system with compensation for short-term PV fluctuations while satisfying water demand. One method uses a PI controller and the other method calculates reference power consumption from water flow reference. Simulations with a PV and a pump system are carried out to find optimum parameters and to compare the methods. Results show that both PI control method and water flow calculation method are useful for satisfying the water demand constraint. The water demand constraint has a little impact to suppression of the short-term power fluctuation in this condition.

Compensation for Photovoltaic Generation Fluctuation by Use of Pump System with Consideration for Water Demand

This paper presents a circuit model for a 100 Ah Lithium Polymer Battery that takes into account the effect of temperature and discharge rates. This is done by studying the behavior of two advanced 100 Ah Lithium Polymer Battery cells under different load condition and at different temperatures, to extract the RC parameters needed to develop the equivalent circuit model. This paper presents a methodology to identify the several parameters of the model. The parameters of the circuit model depend on both, battery cell temperature and discharging current rate. The model is validated by comparing simulation results with experimental data collected through battery cell tests. The simulation results of the battery cell model are obtained using MATLAB, and the experimental data are collected through the battery test system at battery evaluation lab at University of Massachusetts Lowell. This model is useful for optimization of the battery management system which is needed to run a battery bank safely in an electric car.

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Circuit Model of 100 Ah Lithium Polymer Battery Cell

Attempts to fast charge 160 A-h lithium iron phosphate cells at various temperatures are presented in this paper. The tests were done at a charging rate of 2C. The tests were done at three ambient temperatures: 0.0°C, +20°C and +40°C. The current, voltage, and temperature were recorded during the test. It was found that the battery accepts high current for fast charging with little difficulty. The battery charged well at all temperatures. These findings indicate that minimal heating or cooling will be required to compensate for weather conditions in electric vehicles in most climates. The data was obtained at the Battery Evaluation Lab at the University of Massachusetts Lowell which is also briefly described.

Temperature effects on fast charging large format prismatic lithium iron phosphate cells

Still in the rural areas of Rajasthan, India, people are using conventional methods to fetch water from the wells or boreholes. Conventional methods like using animals, which circles around the well to fetch the water are still in use. This paper provides the use of Solar energy to produce electricity to run the water pump for fetching water from well. The paper is based on the theoretical prospect of designing a solar pumping system considering the aspects of Dynamic head, economic feasibility, water requirement and solar irradiance. The theoretical study shows that the proposed system's cost recovery time is half of the life time of system. All the calculations are theoretical

PV powered water well in Rajasthan- India

Different batteries have been evaluated to check their capability in Electric vehicles This paper performs evaluation on 30 Ah Lithium Iron Phosphate battery cells from Gold Peak Different tests (charge- discharge cycle, fast charging test, realistic load test) were done on the battery cells The tests were done at ±00°C, +200°C, +400°C Current, voltage, and temperature were recorded throughout the tests During cycle test, constant current mode exerted exothermic reaction and constant voltage mode exerted endothermic reaction Ah efficiency and Wh efficiency were analyzed for different current rates at different temperatures The battery cell performed Realistic Road Test (RRT) at every temperature but at reduced rate Wh calculations for RRT were performed and presented During fast charging it was observed that at 150 amps charging, battery cells entered in to constant voltage mode The maximum temperature rise observed was at 150 amps discharging and 40°C At 0°C, battery cells did not except high current rate of 150 amps

Dipesh D. Patel

Papers

Circuit Model of 100 Ah Lithium Polymer Battery Cell

Temperature effects on fast charging large format prismatic lithium iron phosphate cells

PV powered water well in Rajasthan- India

Characterization of GP30EVLF 30 Ah Lithium Iron Phosphate battery cells

Dynamic model of supercapacitor using matlab/simulink