Washington :Scientists have developed an all-climate lithium-ion battery that heats itself in sub-zero temperatures and may help electric vehicles function smoothly in winters.
Conventional batteries at below freezing temperatures suffer severe power loss, which leads to slow charging in cold weather, restricted regenerative breaking and reduction of vehicle cruise range by as much as 40 per cent, researchers said.
These problems require larger and more expensive battery packs to compensate for the cold sapping of energy.
“It is a long standing problem that batteries do not perform well at subzero temperatures,” said Chao-Yang Wang from Pennsylvania State University in US.
“This may not be an issue for phones and laptops, but is a huge barrier for electric vehicles, drones, outdoor robots and space applications,” Wang said.
The researchers developed the all-climate battery to weigh only 1.5 per cent more and cost only 0.04 per cent of the base battery.
The battery has multiple applications, but may have the most impact on relieving winter “range anxiety” for electric vehicle owners.
They also designed it to go from -20 to 0 degrees Celsius within 20 seconds and from -5.5 to 0 degrees Celsius in 30 seconds and consume only 3.8 per cent and 5.5 per cent of the cell’s capacity.
This is far less than the 40 per cent loss in conventional lithium ion batteries.
The all-climate battery uses a nickel foil of 50-micrometre thickness with one end attached to the negative terminal and the other extending outside the cell to create a third terminal, researchers said.
A temperature sensor attached to a switch causes electrons to flow through the nickel foil to complete the circuit.
This rapidly heats up the nickel foil through resistance heating and warms the inside of the battery, they said.
Once the battery is at zero degrees Celsius, the switch turns off and the electric current flows in the normal manner.
The findings were published in the journal Nature.