Canada recently signed a new trade agreement with China, reducing tariffs on up to 49,000 Chinese electric vehicles (EVs) each year. By 2030, half of these imported vehicles are anticipated to be “affordable EVs” costing less than $35,000.
This could make electric cars a more budget-friendly option for Canadians. However, public trust remains fragile, shaped largely by fears of EV battery fires.
In 2024, when a high-speed crash on Toronto’s Lake Shore Boulevard resulted in a Tesla bursting into flames, killing four passengers, the images circulated widely online. Months later, another Tesla caught fire on Highway 403 in Ontario, again shutting down traffic.
Evidence shows that the risks of EVs bursting into flames while you drive are low. However, these events have caused some public anxiety.
Solid-state batteries offer a promising new solution. They replace the flammable liquid in existing EV batteries with a solid electrolyte. This reduces the risks of spontaneous combustion when batteries are damaged or when they overheat.
Mercedes-Benz recently trialled an EQS sedan with a solid-state battery. The car drove 1,205 kilometres from Stuttgart in Germany to Malmö in Sweden without a charging stop.
Chinese automaker Chery says it plans to release its first electric vehicle with a solid-state battery later this year. The company says the design could boost energy density and cold-weather performance, with targeted ranges of up to 1,500 kilometres even in sub-zero temperatures.
Canadian researchers are also playing an important role in advancing solid-state technology. I am part of a research team at McMaster University studying battery chemistry at the atomic level to help turn solid-state batteries into a practical technology.
How do lithium-ion batteries work?
EVs rely on lithium-ion batteries rather than gasoline but the basic idea is similar. They store energy and release it when you need it. These batteries are made up of two electrodes: one positive (cathode) and one negative (anode), separated by an electrolyte that allows lithium ions to move between them.
When the battery powers a device or a vehicle, electrons flow through the external circuit to produce electricity, while lithium ions travel inside the battery from the anode to the cathode. Charging the battery simply reverses this process, pushing the lithium ions back to where they started.
How much power a battery can deliver depends largely on how quickly and how many lithium ions can move between the two electrodes.
Today’s batteries rely on liquid electrolytes. This allows lithium ions to move easily and efficiently, giving the car quick acceleration, steady highway performance and consistent response when you press the pedal. How far a car can go on a single charge, however, depends mainly on how much lithium the electrodes can store.
Why do batteries catch fire?
When lithium-ion batteries are damaged or experience internal failures, they can overheat and enter a process known as thermal runaway. This can trigger intense fires that are hard to extinguish and may even reignite hours later.
A major reason is the liquid electrolyte, which is typically made from flammable organic solvents. If the battery overheats, the liquid can act as fuel, worsening the fire. Solid-state battery technology replaces the flammable liquid with a solid electrolyte.
Safer batteries with higher performance?
Solid electrolytes are generally non-volatile and mechanically robust. They reduce the risk of leakage and limit the formation of oxygen-rich volatile decomposition products. They can act as a physical barrier that slows the growth of the lithium filaments that can short-circuit a battery.
Together, these features reduce two major triggers of thermal runaway: internal short circuits and rapid heat-releasing chemical reactions in the electrolyte.
In our research group, we use solid-state nuclear magnetic resonance to understand how lithium ions move inside solid electrolytes. These experiments let us track both the local chemistry and the longer-range ion transport that determine how well a material will work in a battery. By linking these atomic-scale insights to battery performance, we can help design better solid electrolytes for safer electric vehicles.
Beyond safety, solid electrolytes also enable higher-performance batteries. They make it possible to use lithium metal anodes and high-voltage cathodes, which can increase energy density compared to today’s graphite-based batteries.
For EVs, this could mean longer driving range or smaller, lighter battery packs without sacrificing performance.
Why liquid electrolytes still dominate
Despite their safety, liquid electrolytes remain the industry standard.
They provide high ionic conductivity at room temperature, ensuring fast charging, strong acceleration and reliable performance across a wide range of conditions. They also connect well with the electrodes, allowing electricity to flow easily and keeping the battery’s design simpler. Decades of industrial experience have made them relatively inexpensive and easy to manufacture at scale.
In contrast, many solid electrolytes suffer from mechanical brittleness, which means they can crack during battery cycling and lose contact with the electrodes. In addition, solid electrolytes often struggle to make good connections with electrode materials, and chemical reactions at these interfaces can form resistive layers that reduce battery performance.
As a result, while solid-state batteries show great promise, liquid electrolytes have offered the best balance of performance, cost and ease of manufacturing in EVs to date.
Canada’s role in the transition
The recent trade agreement with China could give Canada faster access to the advanced battery technologies already developed at scale in China.
However, many Canadian researchers are already playing an important role in advancing EV battery technology by investigating new electrolyte materials and battery interfaces. Canadian federal programs are supporting battery research, clean-energy initiatives and domestic battery manufacturing, positioning Canada within the global EV transition.
Read more: Lower tariffs on Chinese electric vehicles could boost adoption and diversify Canada’s trade
Advances in materials science, interface engineering and battery chemistry are improving the performance and durability of solid electrolytes. What once existed only in laboratories is moving into pilot production and early vehicle testing.
In the long run, solid electrolytes could reduce fire risk while enabling longer ranges and lighter battery packs, helping EVs become safer.
Taiana Lucia Emmanuel Pereira receives funding from NSERC and MITACS.
This article was originally published on The Conversation. Read the original article.
