Studies on thermal management of lithium ion battery modules

Abstract

There has been a revolutionary transformation in battery energy newlinestorage systems after the introduction of Lithium-Ion Batteries (LIBs) into the newlinecommercial market. Today, LIBs are undisputedly the major source of power newlinefor several interesting applications like the mobile phones, laptops, desktops, newlineElectric Vehicles (EVs), and so on. LIBs have become very popular within a newlineshort span of time due to superior qualities such as lightweight, high energy newlinedensity, high power, large charge/discharge cycles, nil memory effect, newlinenegligible self-discharge rate, compact design and so on. In spite of all the newlinebenefits that LIBs offer, they have severe safety related issues due to excessive newlineheat generation and overheating. Compared to its counterparts, LIBs generate newlinea large amount of heat while under discharging/charging. The heat generated, newlineresults in a significant rise in cell temperatures which lead to critical safety newlineissues like Thermal Runaway (TR), Thermal Propagation (TP), firing and newlineexplosion. Literature data shows that the recommended safe operating newlinetemperature range of LIBs is about 20-40 and#8451;. For a safe operation, LIBs newlinetherefore require efficient Battery Thermal Management Systems (BTMS) to newlinecool the batteries and maintain their temperatures within the safe operating newlinetemperature margin. Several studies have shown that LIBs generate a large newlineamount of heat during discharging/fast charging at high C-rates. C-rates are newlinegenerally defined as the rate at which current is drawn from or charged to the newlinebatteries, w.r.t its nominal rating. For example, a 1C rating of a 1 Ah battery newlinerepresents 1 A current being charged or discharged in 1 hour. A poor dissipation newlineof heat could cause overheating of the batteries triggering TRs and internal newlineshort-circuits. Temperatures during discharging of LIBs can reach about 70 and#8451; newlinefor a 15 Ah LIB at 5C rates, whereas 50 and#8451; for a 40 Ah battery at 2C rates. newlineDeveloping efficient BTMS is therefore crucial for the safe and reliable newlineoperation of LIBs. newline