Warming‐Up Effects of Phase Change Materials on Lithium‐Ion Batteries Operated at Low Temperatures. Issue 9 (6th April 2016) - Ling, Ziye
Abstract: Lithium‐ion battery performance is strongly dependent on thermal conditions, deteriorating dramatically at low temperatures. Herein, a passive thermal management system utilizing RT28/fumed silica composite phase change materials (PCMs) is evaluated for a lithium‐ion battery at temperatures below 5 °C. Taking advantage of the high thermal energy storage capacity, PCMs can store heat and keep a battery warm. The cells with PCMs take much longer before being too cold than cells without PCMs. The improved thermal conditions lead to higher voltages and discharge capacities. In the long term, PCMs increase the average temperature of the battery in continuous cycles and prolong their cycle life by up to 76 %. But the extra thermal mass of the PCM slows the temperature rise so that the cell with PCM fails to perform well at the beginning stages in cold environments. Abstract : Saving phase : Increased temperatures improve the material properties of batteries, leading to increased discharge power, reduced capacity losses, and prolonged cycle life at low temperatures. Phase‐change materials provide large, extra thermal mass to batteries, reducing temperature fluctuations and raising the average temperature of the batteries working in cold environments (below 5 °C). The phase change can be exploited to store thermal energy.