Lithium-ion battery structure that self-heats at low temperatures

Abstract

Lithium-ion batteries suffer severe power loss at temperatures below zero degrees Celsius, limiting their use in applications such as electric cars in cold climates and high-altitude drones. The practical consequences of such power loss are the need for larger, more expensive battery packs to perform engine cold cranking, slow charging in cold weather, restricted regenerative braking, and reduction of vehicle cruise range by as much as 40 per cent. Previous attempts to improve the low-temperature performance of lithium-ion batteries have focused on developing additives to improve the low-temperature behaviour of electrolytes, and on externally heating and insulating the cells. Here we report a lithium-ion battery structure, the 'all-climate battery' cell, that heats itself up from below zero degrees Celsius without requiring external heating devices or electrolyte additives. The self-heating mechanism creates an electrochemical interface that is favourable for high discharge/charge power. We show that the internal warm-up of such a cell to zero degrees Celsius occurs within 20 seconds at minus 20 degrees Celsius and within 30 seconds at minus 30 degrees Celsius, consuming only 3.8 per cent and 5.5 per cent of cell capacity, respectively. The self-heated all-climate battery cell yields a discharge/regeneration power of 1,061/1,425 watts per kilogram at a 50 per cent state of charge and at minus 30 degrees Celsius, delivering 6.4-12.3 times the power of state-of-the-art lithium-ion cells. We expect the all-climate battery to enable engine stop-start technology capable of saving 5-10 per cent of the fuel for 80 million new vehicles manufactured every year. Given that only a small fraction of the battery energy is used for self-heating, we envisage that the all-climate battery cell may also prove useful for plug-in electric vehicles, robotics and space exploration applications.

A Fast Rechargeable Lithium-Ion Battery at Subfreezing Temperatures

“…The latter finding is consistent with the capacity retention result from repetitive activation described in Wang et al 12 In practice, vehicle batteries are thermally insulated and the severity of thermal cycling is far less than that experienced in the −30…”

“…• C to 0 • C. 12 (More recently, we experimentally demonstrated 2.9% battery energy consumption and 12.5 seconds for self-heating from −20…”

“…Cell temperature and charge current expressed in C-rate are displayed in Figure 5b for both ACB and baseline cells. The ACB cell temperature is seen to rise rapidly to [10][11][12][13][14][15][16][17][18][19][20] • C after 90 sec activation, creating a highly reactive electrode-electrolyte interface for high-rate charging. Indeed, the charge current starts at 3C and remains higher than 2.5C as the ACB cell is charged toward 80% SOC.…”

“…12 In the latter case, heat must warm up the battery casing before benefiting electrodes and electrolyte inside it, causing low heating speed and high energy consumption. It is generally estimated that for battery heating from −20…”

Integrated computation model of lithium-ion battery subject to nail penetration

“…The sales of electrical vehicles (EVs) have increased in the last few years [1], and lithium-ion batteries (LIBs) as promising alternative energy sources for use in EVs [2,3]. LIB safety has become one of the main topics with regard to passenger safety because LIBs are frequently used in vehicles [4,5].…”