What is Battery Usable Energy
Description
The battery usable energy refers to the electrical energy that the battery can actually release and use for external devices under certain conditions,here’s a more detailed explanation:
1.Energy conversion aspect
Batteries convert stored chemical energy into electricity through chemical reactions inside them. Under ideal conditions, all the chemical energy stored in the battery should be able to be converted into electrical energy for external use, but in fact due to various factors, only a part of the chemical energy can be effectively converted into usable electrical energy, which is the available energy of the battery. For example, in lithium-ion batteries, the migration of lithium ions between the positive and negative electrodes is accompanied by the transfer of electrons, resulting in an electric current, but in the process, some energy will be lost in the form of heat, resulting in not all of the chemical energy can be converted into usable electrical energy.
2.Influencing factors
2.1 Battery characteristics
Including electrode material, electrolyte, battery structure and so on,different electrode materials have different energy storage and release capabilities, which will affect the energy conversion efficiency of the battery and the amount of available energy,for example, lithium cobalt acid battery energy density is high, but the cycle performance is relatively poor, as the number of use increases, the available energy will gradually decrease; Although the energy density of lithium iron phosphate batteries is slightly lower, the cycle stability is good, and the available energy can be maintained relatively stable for a long time. The conductivity and chemical stability of the electrolyte also affect the ion transport efficiency, which in turn affects the battery usable energy.
2.2 Conditions of use
The temperature has a significant effect on the available energy of the battery. At low temperature, the chemical reaction rate inside the battery slows down, the viscosity of the electrolyte increases, the ion diffusion is difficult, the internal resistance of the battery increases, and the available energy will be significantly reduced. High temperatures may lead to increased side reactions within the battery, accelerate battery aging, and reduce available energy. In addition, the rate of charge and discharge also affects the available energy. During rapid charge and discharge, there will be a large polarization inside the battery, so that the actual working voltage of the battery deviates from the ideal voltage, resulting in energy loss and reducing the battery usable energy.
3.Evaluation method
The available energy of the battery is usually assessed through specific standard tests. For example, under standard temperature and humidity conditions, the battery is charged and discharged at a specified rate of charge and discharge cycle test, and the total amount of electric energy that the battery can output during the whole process is measured to determine the available energy of the battery under the test conditions,however, in actual use, due to the different working currents and environmental conditions of the equipment, the usable energy of the battery will vary.
4.Conclusion
The battery usable energy is an important index that comprehensively reflects the performance of a battery. It is affected by many factors such as the battery’s own characteristics and operating conditions. It is of key significance for the rational use of the battery, the design of the battery management system and the evaluation of the battery’s performance in different application scenarios.