The electric vehicle industry is growing fast. Despite the pandemic, global sales of electric cars in 2020 rose by 43% to more than 3 million. The International Energy Agency projects that by 2030, 30% of cars on the road will be battery-powered electric vehicles.
Yet the adoption of all-electric vehicles and hybrid-electric vehicles is facing various hurdles. Consumers often cite limited driving range and charging infrastructure and high maintenance costs.
The biggest challenge is in battery technology. Electric car batteries are still too technologically limited and expensive. There must be major advances in battery technology to make electric vehicles viable.
These hurdles must be overcome for us to have the reality of an electrified vehicle fleet. Here are the biggest challenges faced by battery technology.
This is the amount of energy stored per unit volume or weight. One of the major concerns over electric cars is the driving range. The battery’s energy density is one of the main factors that determine the driving range.
There’s a limit to space and weight in electric cars. This means car batteries must have higher energy densities to drive longer distances.
Among current battery technology, lithium-ion batteries have one of the highest densities. Yet this is still much less than that of gasoline. Reaching a 200 to 300-mile driving range needs a big amount of batteries.
A problem with lithium-ion batteries its physicochemical limit. As they reach this limit, there needs to be new battery technology to further the driving range.
New battery designs include lithium-sulfur, lithium-air, and magnesium-ion. These new battery technologies have higher theoretical densities than lithium-ion batteries.
The downside is they suffer from other issues like safety and poor cyclability. This prevents their full application in electric vehicles.
Electric vehicles’ battery packs also have other components besides the cells. These include thermal parts, busbars, and battery management systems.
Taken together, this added hardware also lessens energy densities. For energy density to increase, cell design and pack efficiency must also improve.
Faster Recharge and Power Capacity
Energy density is also important for electric cars’ charging efficiency. You need a higher energy density to recapture more energy in a short time.
Most current electric vehicles take hours to get a full charge. This is fine if say you’re charging overnight or during work. Yet this becomes inconvenient when driving longer distances and needing frequent recharging.
There have been recent improvements in electric cars’ charge capability. Yet the goal is to have electric cars charge to 80% SOC within 10-15 minutes. This means there need to be more advances along the line.
Cell chemistry and material properties are the main obstacles to faster charging. There have been several methods used to increase the charging rate.
One is ore-warming cells to improve electrode transfer. Another is using a higher voltage system.
There have also been battery issues resulting in car recalls. One instance is the Chevrolet Bolt battery issues.
There needs to be more optimized charging algorithms for future electric vehicles. This will allow faster charging without affecting battery life and safety.
Battery cells in electric vehicles have constraints to maximize performance.
To replace a cell from a pack, reassembling the entire module is usually needed. This can be expensive. As a result, electric car batteries are generally not serviceable.
It’s also because of this that it’s expected for a battery’s life to be the same as the vehicle’s life which is 15 years. The battery life refers to the timeframe when its capacity has decreased to 80% from the original.
Finding ways to recycle batteries is gaining traction. They still contain high-value metals like cobalt. Yet the process to extract them is expensive. There need to be more cost-effective methods of recycling car batteries.
Electric vehicles have lower operating costs than regular vehicles. Yet their high upfront price remains a major hurdle to wider adoption.
Battery cost determines the price of electric vehicles. Reducing the cost of batteries will make electric cars more affordable.
Scale or engineering improvements can reduce battery costs. Yet a big chunk of the costs depends on innovation in areas like raw materials. Using high energy density materials is one way to reduce cost.
Another is replacing current materials with cheaper ones. Cobalt is usually used in current battery technology yet it is also expensive.
Meanwhile, replacing cobalt will impact battery safety and cycle life. Thus, one of the big challenges in reducing cost is keeping the same performance.
Performance in Different Environments
An electric vehicle’s battery is an electrochemical system. Thus, environmental factors like temperature affect its performance. In particular, the charging/discharging rate.
For example, higher temperatures allow for a higher charging rate. Yet this increases the SEI growth rate and shortens battery life.
Meanwhile, lower temperatures slow down SEI growth. Yet this also motivates lithium plating.
Current technologies can optimize car batteries for either high or low temperatures. However, it’s hard to keep the same performance for different temperatures. Maintaining performance under different conditions is crucial.
Using effective thermal management systems that maintain temperature is one solution. Yet limited contact area hampers efficient cooling or heating.
Battery failure can lead to catastrophic consequences like fire. Because of this, safety is one of the most important factors in battery design.
There are regulations for electric vehicles and batteries in many countries or regions. They involve a series of tests before they’re allowed to enter the market.
These tests induce battery failure through external abuse or internal mechanisms. The aim is to trigger short-circuits that lead to thermal runaway. New battery materials are seeing development to reduce the risk of thermal runaway.
Besides materials, safety features are also included to lessen safety risks. These include fuse, vent, and current interrupt device. There’s also a management system that tracks voltage and temperature.
Advances in Battery Technology Is the Key to a Sustainable Future
The fast-growing electric vehicle sector, sustainability, climate change are calling for innovations. Despite the industry’s growth, challenges in battery technology are still a significant obstacle. Problems in energy density, charging, and performance must be overcome for wider adoption.
Want to know more about the most recent advances in battery technology? Check out our other articles in this section.
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