Energy

Lithium-ion battery warms itself in cold environments to maintain performance

Lithium-ion battery warms itse...
The all-climate battery rapidly self-heats in cold environments
The all-climate battery rapidly self-heats in cold environments
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The all-climate battery rapidly self-heats in cold environments
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The all-climate battery rapidly self-heats in cold environments
The all-climate battery rapidly self-heats in cold environments
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The all-climate battery rapidly self-heats in cold environments

Extreme temperatures can seriously compromise the performance of lithium batteries. We've seen a number of developments promising to reduce the risk of them overheating and catching fire, but at the other end of the scale, freezing temperatures aren't too friendly either, often leading to substantial power loss. In an advance that could have ramifications for everything from electric vehicles to space exploration, researchers have built a lithium battery that warms itself up to battle the winter chill.

While a battery that maintains its performance in cold temperatures could prove useful in many applications, including space travel and high-flying drones, in the eyes of Penn State University researchers, alleviating range anxiety for electric vehicles is one of the more promising. The power loss suffered in electric vehicles at below freezing temperatures can result in slow charging, impact regenerative braking and cut cruising range by as much as 40 percent.

We have seen EV manufacturers take steps to address these drawbacks. In 2010, for example, Ford announced an all-electric Focus with a thermal management system, which either heats or chills a coolant and pumps it through the battery system to regulate the temperature. But by and large, cold environments still present a real challenge to the performance of electric vehicles.

The Penn State team approached this problem by fitting a lithium battery with a nickel foil attached at one end to the negative terminal. An integrated temperature sensor reroutes the current through the nickel foil, warming the battery from the inside through resistance heating until it returns to above freezing temperature, and then switches off and leaves the battery to function normally.

In testing, the battery was able to warm from -4 ° Fahrenheit up to 32 ° F (-20 ° C to 0 ° C) in 20 seconds, and - 22 ° F to 32 ° F (-30 ° C to 0 ° C) in 30 seconds. And it did so while consuming just 3.8 percent and 5.5 percent of the battery's capacity respectively. By comparison, the team points out, this is a significant improvement on the 40 percent loss of capacity experienced by conventional lithium batteries in cold temperatures. In addition, the Penn State battery is only 1.5 percent heavier and costs 0.04 percent more than a conventional lithium-ion battery.

The research was published in the journal Nature.

Source: Pennsylvania State University

6 comments
RikuPasonen
According to local taxi driver, Tesla Model S gets 400 km/charge even in Finnish winter and he says it is the best taxi car he has driven. Already 120'000km on the clock. 8 year warranty works wonders for taxi drivers. The Finnish driver is planning to keep his car for five years. With that said, If there was a cold climate problem, Tesla has already cracked it :)
Daishi
I'm sure thermal management on batteries could end up being common. GM built a battery simulation lab with a bunch of big blue climate controlled boxes meant to simulate weather from various parts of the world while they ran sample packs through test loads. For their design they concluded that a nickel heavy cell composition dissipate heat better and could mean less work for the external pack cooling system.
I'm sure we'll see lots of interesting approaches for thermal management systems going forward too. In relation to heating the pack in the cold one thing I wanted to mention is while the pack is charging (or in use from driving) it's going to produce some heat on its own. This means the time when the thermal management system is the only available source to heat the battery would be while it's not charging or driving so the power requirement to do this may not be excessive.
What's cool is ICE's have tons of generations and iterations of improvements in efficiency so 0.1% gains without major tradeoffs are difficult where lithium ion packs in cars are mostly a new thing so large efficiency gains are still possible to find.
wle
i don;t get it..
is the capacity really ''lost'' - or just unavailable while the battery is cold?
if it is the latter, then don;t all batteries self warm eventually, and after they do, then the reduced capacity is then available..?
wle
MDR54
Why don't EV's in cold environments have a small IC engine to produce enough waste heat for the passenger compartment and the batteries. Hooking it up to an alternator would also increase the EV's range. I also don't understand why houses in the north don't have Natural Gas powered IC engines producing electricity. The waste heat could be used to warm the house. Any excess electricity could be sold back to the utility company to help defray the fuel and maintenance costs of operating the IC engine.
Road tar
Mdr. Run the numbers, if they are good, you might have a good business idea.
ArthurWolek
This RikuPasonen below is one clever master debater. Taxis are being used constantly, so the energy loss due to heating the battery in a cold climate is not very significant. This is why Musk and others who favor BEVs know that the future in climates where the temperature is outside the 40F to 85F range has to be ridesharing, when BEVs are being used constantly so the energy used to constantly heat or cool the battery will be more on the order of 5% to 10% and not 50%. If, on the other hand, one lives in a very cold climate and only drives something like 10 miles a day, a Lamborghini R8.270 DCR would be a much better choice for the environment and would not require a $30,000 battery replacement every year. I have never seen a single TESLA in Alaska, and anyone who drives a BEV in Alaska is committing a crime against the environment.