White walkers can’t have EVs. Not because they are lifeless zombies who probably can’t drive, but because the extreme cold of the north would severely impact the lithium batteries. Also, the region is quite large, so EVs would likely run out of juice before they could cover a good portion of its 1,100-mile length. Scientists in China may have solved both problems with a new lithium battery electrolyte that withstands cold temperatures and could double EV range.
A joint team of researchers from Nankai University in Tianjin and the Shanghai Institute of Space Power Sources (SISP) has developed a hydrofluorocarbon-based electrolyte that significantly enhances the performance of lithium batteries. As reported by the South China Morning Post, the new electrolyte more than doubles the energy density of existing batteries at room temperature, meaning batteries of the same size can last twice as long!
The researchers also claim that the new electrolyte remains stable in extreme cold, allowing batteries to function seamlessly in temperatures as low as -94 ºF (-70 ºC), well over 2.5 times the temperature of your refrigerator.
Chemical batteries, such as lithium batteries, utilize electrolytes – a chemical medium that allows ions to flow between the positive and negative electrodes, converting stored chemical energy into electrical current. In lithium batteries, the electrolytes are usually nitrogen- and oxygen-based compounds, mainly because of their effectiveness at dissolving lithium salts.
However, these electrolytes are sensitive to operating temperatures. Cold temperatures increase viscosity and slow down ion mobility, reducing charge transfer efficiency. When this happens, the battery delivers less power, takes longer to charge, and loses usable capacity, providing less runtime than its stored energy would suggest. This is why lithium batteries appear to die quickly in extreme cold. In certain conditions, such as charging the battery when the temperature is below 32 °F (0 ºC), permanent damage may occur.
In the study published in Nature, the researchers outlined how their solution, synthesized hydrofluorocarbon-based (hydrogen, fluorine, and carbon) electrolytes, eliminates this problem in lithium batteries. The cold-resistant electrolyte offers improved stability and lower viscosity at low temperatures, enabling batteries to continue operating efficiently below -94 °F.
Another outstanding feature of the electrolyte is its energy density – the amount of charge it can store per weight. In the study, the team created lithium metal pouch cells that achieved an energy density of 317 watt-hours per pound (Wh/lb) at room temperature. The cells still maintained a density of 181 Wh/lb at -50 °F (-46 ºC).
In comparison, conventional lithium batteries, such as those found in Tesla EVs, have an energy density of 73-136 Wh/lb at room temperature. This figure more than halves when temperatures fall to just -4 °F (-20 ºC).
Technically speaking, the researcher’s electrolyte could triple the range of some EVs with the same battery size!
“For the same mass of lithium battery, the room temperature energy storage capacity is increased by two to three times,” said study author Li Yong, a researcher at SISP.
Beyond the automotive industry, this development could have far-reaching implications across many sectors and everyday life. We are talking drones, robots, smartphones, and consumer electronics that last twice as long while still being able to operate efficiently in extreme cold.
Research robots operating in Antarctica could function reliably, while subsea exploration vehicles could significantly extend their operational range. Similarly, satellites and spacecraft, which endure extreme temperature swings in orbit, could benefit from more stable and predictable power systems. The list goes on and on.
Before we get carried away, it’s important to note that the electrolytes are not exactly “all weather” … yet. The team noted that the electrolyte’s high-temperature stability still needs improvement. Should they succeed in raising the boiling point of the electrolyte, we could have a true all-climate solution.
Source: Nature
