Why Do EV Batteries Catch Fire? And Here Is How I Found The Answer- Exponent Energy
EV Batteries: As a result of the recent EV fire, many EV aficionados and would-be owners have been hesitant to make the switch to electric vehicles from gasoline ones.
Big OEMs and EV experts are now asking why lithium-ion batteries in electric scooters and electric automobiles catch fire, and what solutions there are. According to Exponent Energy, a pioneer in the field of fast-charging batteries, here’s how it works:
What causes EV batteries to explode?
Before a thermal runaway event may occur in lithium-ion cells, they must reach temperatures of several hundred degrees Celsius (the fires you see are the result of thermal runaway).
The temperature at which most current batteries shut down is between 45 and 55 degrees Celsius. It is impossible to raise the temperature of the battery to a few hundred degrees Celsius by using only the heat generated by the batteries or ambient heat.
(Of course, climate change is a fact, and summers are becoming hotter). The temperature of 100°C isn’t too hot, and the battery doesn’t generate that much heat in absolute terms compared to its thermal mass (
Every battery has three metrics: ‘Performance’ ‘Battery Life’ and ‘Safety.”
Summer heat and poor thermal management have a negative impact on productivity and life expectancy, but they do not cause fires. Similar to using a smartphone while it’s been left out in the sun, this causes your phone to run slower and heat up, both of which reduce its lifespan. That doesn’t mean they don’t pose a risk, though
Then why do electric vehicle batteries catch on fire?
Short circuits resulting in unregulated current cause 99 percent of battery fires. Thermal runaway occurs as a result of the cell’s temperature rising by several hundred degrees Celsius.
There are three main causes of short circuits:
1. Poor quality of cells
2. The battery is poorly designed (the way cells are connected & packaged)
3. The BMS is not up to par (management of cells via sensing & software intelligence)
It is important to have high-quality cells.
As a result of poor cell quality, an internal short circuit can occur. As a result of design flaws, the anode and cathode are incorrectly connected internally, resulting in a short circuit. Eventually, this will result in an out-of-control current. Thermal Runaway is blamed on him.
Cellular packaging is critical.
Short-circuiting is not usually the result of poor cell quality. Packaging for batteries has a significant bearing on their safety. Packaging refers to how you put the cells together, and how you electrically connect to them and hold them mechanically.
Having a bad BMS = Overcharging Cells cycle between the zero and one hundred percent charge states, which are basically equivalent (SOC)
- From 2.8V to 3.6V, LFP can be used.
- 2.8 to 4.2 volts of NMC
The production of lithium dendrites can be greatly accelerated even if NMC is overcharged by a little 0.05V.
On the ups and downs of excessive charging
A fire can start as a result of an overcharged battery, which causes cells to swell, collide, short-circuit, and eventually explode. You don’t have to envision it.
What is the answer? then
Battery safety isn’t a problem that can be solved simply by spending money on better cells.
The following people are all affected by the issue:
- devices with moving parts (we need better-designed packs)
- Systems that use electronic components (we need accurate BMS sensing and impedance management)
- We require more intelligent software and code that is less prone to errors and crashes.
In addition, a lot of testing is required.
TEST. TEST. TEST.
So, we break things in our labs before putting them out in the real world.Despite our best efforts, our battery pack detonated (yes, deliberately). We overcharged our battery pack to see whether it would catch fire.
Propagation (picture hundreds of cells experiencing thermal runaway one after the other) was the specific focus of the study.
When it comes to pushing the boundaries, you need to be prepared with all the necessary safety gear.