Sodium-Ion Batteries Are Cheaper & Safer For EVs, So Why Don’t We Use Them?
Advancements in battery technology are the reason today’s EVs are practical replacements for internal combustion engine (ICE) cars. Lithium-ion is the chosen option because it offers high power density, long service life, low self-discharge, and various other advantages.
However, sodium-ion batteries offer benefits that could make them a better option for the future. Firstly, it’s far more abundant than lithium, which means it’s available everywhere including in seawater. They use aluminum instead of copper as is the case for lithium-based batteries, making them cheaper to produce.
Sodium-ion batteries charge quicker than their lithium-ion counterparts and have a much longer lifespan too. The former is also much more tolerant towards extreme temperatures compared to the latter, making it safer to operate as well.
They are also environmentally friendly when stored for lengthy periods of time. In addition to this, they can completely deplete their charge to 0% and still not face any damage. This isn’t the case for lithium-ion ones because they need to maintain a charge level that’s above a certain threshold.
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Thermal runaway is a problem that causes lithium-ion batteries to spontaneously catch fire. It happens because a puncture, defect or overheating of a cell could result in a sudden and uncontrollable rise in temperature.
This could then lead it to burst into flames, which may affect adjacent cells as well resulting in a chain reaction. If left unchecked, the fire could spread and eventually engulf the entire vehicle.
Sodium-ion batteries don’t present the same risk of thermal runaway issues, which make them safer and more robust for most applications. But if they offer so many benefits over lithium-ion ones, why aren’t they being used in electric vehicles?
This technology is still in its infancy and further developments are needed to overcome certain hurdles. One of them is their lower energy density compared to lithium-ion cells. This means sodium-ion batteries need to be larger in size to store the same amount of charge, which isn’t ideal for electric cars.
Sodium-ion batteries are currently used in micro cars as well as the energy storage sector where weight and storage space are not factors that need to be considered. However, the race is on to develop more useful versions of these batteries. BYD is building a facility in China that will manufacture them for smaller EVs and scooters.
This technology has the potential to advance further, which could give rise to more environmentally friendly production of such batteries for EVs of the future.
