INVESTIGATION OF THE ENERGY CAPACITY OF LITHIUM BATTERIES AT DIFFERENT AMBIENT TEMPERATURES

Abstract

Today, the popularity of renewable energy is constantly growing, so rising energy costs are driving the development and expansion of energy storage systems. Battery storage technologies allow for the efficient use of excess energy during times of shortage, which is why more and more consumers are choosing to store energy in batteries. By installing electricity storage batteries, consumers can not only store electricity, but also sell it on the market when prices are highest. The aim of this study is to determine the most suitable type of battery for operation at different temperatures. For this purpose, a special research stand was designed to compare different types of small-capacity batteries: lithium-ion (Li-Ion), lithium polymer (Li-Po) and lithium iron phosphate (LiFePO4). During the experiment, the operating temperature of the batteries was changed (+23 °C, +7 °C, –17 °C), and the batteries were discharged to their minimum capacity, applying a constant load from 1 A to 2.5 A, depending on the battery type and number of cells. The results of the study showed that the capacity of all types of lithium batteries decreased by 3–28% at positive temperatures. Based on the results of the experiment, it was determined that Li-Po batteries could store an average of 9.14 Wh of energy, and at –17°C their capacity decreased by 4%. LiFePO₄ batteries could store an average of 6.36 Wh of energy, and at –17°C their capacity decreased by 66%. Li-ion batteries could store an average of 6.33 Wh of energy, and at –17°C their capacity decreased by 6%. These results allow us to assess the suitability of batteries for use at different temperatures in order to ensure efficient energy storage and use.