The infamous Texas Arctic freeze of five years ago exposed a key vulnerability of electric vehicles: Many drivers were forced to abandon their vehicles after being left stranded with dead batteries and no charging station in sight. While cold weather can lower driving range by ~10%, unusually low temperatures can cut it by up to 40% while increasing charging time by 300%. Thankfully, this could soon become a thing of the past: Chinese researchers have developed an all-weather battery electrolyte that is not only capable of maintaining high energy efficiency in freezing weather but also boost the driving range of electric vehicles.
Developed by Nankai University and the Shanghai Institute of Space Power-Sources (SISP), the new electrolyte enables lithium-metal batteries to reach an energy density exceeding 700Wh/kg, more than the ~300Wh/kg typically found in current high-end lithium-ion batteries, potentially boosting EV driving range from the current 500-600km to over 1,000 km.
The fluorine-based electrolyte improves ion transfer and stability, overcoming traditional solvent limitations that cause poor performance in cold weather. Indeed, unlike traditional liquid electrolytes that thicken and fail in freezing weather, this HFC-based system maintains an energy density of ~400 Wh/km at -50 °C, and continues to function at -70 °C. For some perspective, the lowest temperature ever recorded in the Northern Hemisphere is -69.6 °C. The researchers replaced the traditional oxygen-coordination framework with a fluorine-coordinated system using monofluorinated alkane solvents. Fluorine’s weaker pull on lithium ions allows for faster ion release and transfer, resolving the typical conflict between fast ion movement and quick charge transfer. Further, the electrolyte comes in a semi-solid-state, which reduces flammable liquid components and improves fire resistance even at high temperatures.
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Even better, the “wonder” batteries could become an everyday reality sooner rather than later, with the researchers and industry partners like China Automotive New Energy Battery Technology Co. aiming for limited mass production later in the current year. Beyond passenger vehicles, the technology is expected to be deployed in a wider array of devices that operate in hostile environments including spacecraft, drones and intelligent robots that operate in frigid or high-altitude environments.
EV battery technology is experiencing a rapid evolution driven by the demand for longer range, faster charging, improved safety, and lower costs. Regarded as the next major breakthrough, Solid-State Batteries (SSBs) replace flammable liquid electrolytes with solid materials (e.g., ceramics or polymers), allowing for higher energy density, faster charging and reduced fire risk. Toyota plans to commercialize solid-state batteries by 2027-2028, featuring 1,000+ km range and 10-minute charging. Toyota is partnering with companies like Idemitsu for solid electrolyte production and scaling up its manufacturing capabilities for early manufacturing. But Toyota is not alone. QuantumScape has demonstrated solid-state battery cells that exceeded 1,000 full charge/discharge cycles. The 24-layer prototype cells maintain an impressive 95% capacity after 1,000 cycles, exceeding the industry standard target (typically 80% retention after 700-800 cycles). This level of performance suggests an electric vehicle could travel over 500,000 kilometers (~310,000 miles) without significant loss of range. Meanwhile, Samsung SDI is on track to mass-produce solid-state batteries (ASSBs) by 2027, featuring a 600-mile range, 9-minute charging, and 20-year lifespan for high-end EVs.
That said, SSBs are not the only game in town when it comes to advanced EV batteries.
Silicon Anode Batteries are replacing traditional graphite anodes with silicon, thus allowing batteries to store more lithium ions, increasing energy density and decreasing weight. Companies like Amprius Technologies are developing silicon anodes that can deliver up to 500+ Wh/kg, while Sila Nanotechnologies is partnering with Panasonic to implement silicon anodes in production lines. Then there are Lithium Iron Phosphate (LFP/LMFP) batteries favored for their lower cost, increased safety (no oxygen in the chemistry) and longer lifespan compared to nickel-based batteries. LFP batteries do not use nickel or cobalt, which are expensive and raise ethical mining concerns. Tesla Inc. (NASDAQ:TSLA) has already switched to LFP batteries for its standard-range vehicles and energy storage products. The tradeoff here is a lower driving range, with LFP batteries only capable of 320–480 km on a full charge. However, newer LFP battery packs are extending this range, with some Chinese market developments aiming for over 1,000 km.
Other promising advancements in the space include Graphene-Enhanced Batteries that use graphene in their electrodes to improve conductivity, enabling faster charging and better heat management; Low-cost Sodium-Ion Batteries (SIBs) that utilize abundant sodium instead of lithium or cobalt as well as Lithium-Sulfur (Li-S) Batteries that promise higher energy densities.
By Alex Kimani for Oilprice.com
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