In China’s Tier 1 and 2 cities, where EV policies are actively promoted, taxi fleets mostly choose EVs for easier registration and more government incentives. Under Northeast China’s freezing weather, these taxi drivers face a harsh reality: faster power consumption and slower charging efficiency. In frigid temperatures, long queues for charging are a common sight for taxi drivers, which, in turn, has become a primary challenge for EV owners living in high-latitude regions with cold weather to overcome.
Before discussing this topic, let’s go back to the inventors of lithium batteries, which are the winners of the 2019 Nobel Prize in Chemistry: John B. Goodenough, M. Stanley Whittingham, and Akira Yoshino. The Nobel committee’s 2019 press release specifically mentioned: “This rechargeable battery laid the foundation of wireless electronics such as mobile phones and laptops. It also makes a fossil fuel-free world possible, as it is used for everything from powering electric cars to storing energy from renewable sources.” Lithium, the third lightest element in the periodic table, has the highest energy density in solid-state batteries. However, due to their higher activity, lithium batteries are in danger of flammation and explosion during charging, which had always been an enormous barrier for earlier technologies. Due to the three Nobel Prize winners’ solutions to these obstacles in the 70s and 80s, they’ve made an immense contribution to developing lithium-ion batteries and changed humankind’s industrial stance in the petroleum age. These efforts made green energy replacements for fossil fuels possible and indirectly enabled renewable energy, such as solar and wind power, to blossom with the aid of lithium energy storage.
Even though the danger of charging lithium batteries is largely obsolete, their performance still falters under extreme temperatures. As a result, in EVs’ most crucial triad (battery, electric control, motor) technologies, battery management systems’ primary objective is to maintain optimal temperature for battery module performance. Lithium batteries’ charging and discharging processes are essentially chemical reactions with exothermic reactions. Mitigating the risks of battery swelling and subsequent burning and explosion due to thermal energy release has made EV battery cooling systems a crucial part of EV design. As opposed to cooling systems, how to improve lithium batteries’ low performance in low temperatures is not so prioritized.
According to lithium batteries’ chemical properties, charging below freezing point will cause lithium buildup (plating) and battery damage. Consequently, in freezing weather, the charging process will devote part of its time to heating the battery to ideal temperatures, taking up more time to charge the vehicle. At the same time, driving EVs in freezing environments will result in less range due to part of the power going to heating.
The high-latitude Norway has the highest EV sales ratio worldwide. Norwegian experts and automakers are devising makeshift strategies to tackle these issues and extend EVs’ ranges in the winter, including advising drivers to plug in the charging cable when parking to maintain temperature, setting departure time on charging posts to pre-heat and charge EVs, etc., to alleviate inconveniences.
All the current mass-produced BEVs use NCA, NCM, and LFP for lithium-ion batteries’ positive electrode material. Whichever type, they are all susceptible to lower temperatures causing low performance, of which the lower-energy-density and cobalt-less LFP is impacted the most. Although Taiwan’s sub-tropical climate reduces this issue to a minor annoyance, its industry still has to face the matter in the close-linked global auto supply chain. Possible solutions include a few types:
1. NCMA, nickel-cobalt-manganese-aluminum-ion battery:
Announced by the US’s GM and South Korea’s LG Energy Solution in 2020, Ultium Cells is based on an American Chemical Society publication in 2019 by professors from Korea’s Hanyang University and Germany’s Institute of Energy and Climate Research. Aside from better energy density, lower costs, better cycle life, and stability than NCA/NCM, this type of NCMA also boasts better performance under the same temperature. As a side note, Tesla, the leader in the EV market, stated Model Y would utilize Ultium Cells, though official announcements are yet to come out in the open.
2. Sodium-ion battery:
Aside from worse energy density than lithium-ion batteries, sodium-ion batteries have enormous advantages regarding resource costs and low-temperature performance. As many battery manufacturers are actively preparing for mass production, Chinese companies (such as CATL, BYD, Gotion High-tech, etc.) are the most aggressive.
3. Wireless power transfer (WPT):
EVs’ wireless charging utilizes electromagnetic induction and the chassis & the ground coil’s resonance effect to direct the electric current with the magnetic field toward the battery set. SAE J2954 is the current standard for consumer-grade EVs, supporting 3.3kW to 11kW. However, due to the ground chargers’ much higher installation cost than charging posts (3~6 times higher while both being 8kW), the technology is still far from commercialization. However, the vehicle receiver units are much more economical, so Hyundai and BYD have already installed WPT modules on several EV models to prepare for future autonomous vehicles that cannot self-charge at charging stations. In conclusion, this safer and more convenient wireless charging system is also a worthy contender to tackle the temperature factor in EV charging.
4. FCEVs and hydrogen ICEs:
As many FCEVs are already in mass production and market available, hydrogen fuel’s storage and equipment deployment have higher costs, rendering the technology relatively disadvantaged in the market. Of course, the development of Toyota’s many recent hydrogen ICE concepts is still worthy of our attention.
As global industries enter EV development’s ascension cycle, manufacturers and market cap rush to grasp the rare opportunity to grow. We can use a more optimistic attitude toward these performance issues during the development and expect more diverse and customer-oriented products to launch in the future.
About the author - Kenny Liu
Graduated from Dept. of Aeronautics and Astronautics, Cheng Kung University in 1988, started his auto industry career since July 1990 after two year military service. Starting as a service engineer and a temp technician, product marketing specialist in Peugeot/ Daihatsu, marketing and dealer channel specialist in VW LCV from March 1992, then field manager in GM Taiwan from Feb. 1994, sales and service / parts head in Ford Lio-Ho from Sep. 1998 till retirement in May 2019. Kenny then started to work for JLR Taiwan as sales/service head and consultant/ lecturer. After that, he was invited to work at a Suzuki dealer of Taipei as the general manager until April 2022.