Here’s Why Solid State Batteries Might Not Be The Next Best Thing

Summary

• Automakers are pushing for electric cars but must address autonomy & charging times.
• Solid-state batteries are hailed as a solution, but CATL CEO questions their practicality & safety.
• Toyota backs solid-state batteries, but faces challenges in development & deployment.

As everyone knows by now, the electrification of transportation, primarily cars, is on the rise, faster than ever. Automakers are pulling out all the stops to optimize their electric powertrains in order to appeal to customers who have decided that their next vehicle will be electric.

For electric cars to fully establish themselves as a compelling alternative that convinces the undecided, there are several issues the auto industry needs to address beyond just the cost of the vehicle. The most important ones include increasing autonomy and reducing charging times. For several brands, such as Toyota and Nissan, one possible solution is solid-state batteries.

However, just a few days ago, the founder of the world’s largest supplier of lithium-ion batteries, CATL, dismissed solid-state batteries as “impractical and unsafe”. He alleged that claims of their superiority ignore the real-world limitations of the technology. This constitutes a significant blow to the industry, as such comments from a market leader do not inspire confidence in future projects from these automakers.

In order to give you the most up-to-date and accurate information possible, the data used to compile this article was sourced from various manufacturer websites and other authoritative sources, including CarBuzz, Toyota, and CATL.

Ensuring Solid-State Batteries’ Future Viability Would Require Implementing A Challenging Chemical Process

As of today, it’s clear that lithium-ion batteries are the most common battery type employed in new electric vehicles, widely adopted by car manufacturers such as Tesla, Hyundai, Ford, Porsche, and MG. However, due to the incredible market investment in this product, technological advancements are leading to the possible emergence of other alternatives, and this is where solid-state batteries come into play.

Seen broadly as a “silver bullet” for addressing driving range anxiety in electric vehicles, with Toyota claiming they could provide up to 745 miles of range after just a 10-minute charge of a completely depleted battery, they are also said to be cheaper, thus improving affordability and removing another significant barrier to potential electric car buyers.

Even so, after many years of research and development, these promises seem to still be far from being fulfilled, as a viable solid-state battery has yet to be developed, according to Dr. Robin Zeng, the chief of CATL.

CATL’s CEO Expresses Concerns About The Viability Of The Solid-State Batteries

To provide some context, Chinese-based CATL (Contemporary Amperex Technology Company Limited) is the world’s largest producer of lithium-ion batteries, holding a 36.8 percent share of the global supply in 2023, ahead of BYD’s 15.8 percent.

Dr. Robin Zeng, the current CEO of CATL, informed the Financial Times that the highly anticipated solid-state battery technology was unreliable, lacked durability, and even presented unresolved safety concerns in its current form. Furthermore, he states that he doesn’t understand what’s with all the hype, as concrete achievements have yet to be reached.

Zeng – Nicknamed The “Battery King” – Told The Financial Times.

We fully support solid-state. I have been investing in this for 10 years. I watch the development made by people working on solid-state almost every month, so I know all the progress, and somehow we still have these showstoppers.

The Main Challenge Arises From Requiring A Whole New Chemistry For Battery Development

Probably very few people know as much as he does in the world about this technology, and that’s why his opinion carries so much weight. When delving into the core problem, he explains that the big issue is that an entirely new type of chemistry is required in the development of the battery, one that utilizes pure lithium metal for the anode electrode.

However, this brings about other problems that have yet to find a solution. On one hand, the system needs to be kept under extreme pressure, which poses a threat when batteries expand during recharging. On the other hand, the lithium in these batteries would react with oxygen if the battery housing were pierced in an accident, potentially releasing toxic lithium hydroxide, which could harm the vehicle occupants, emergency services, and other road users. Needless to say, this is not desirable.

To make it even worse, due to the pressurization issues, Zeng says that the battery would not be able to withstand many charging cycles, severely compromising its commercial viability.

Zeng Added:

It cannot last many [charging] cycles, maybe 10 cycles. So how can you make it commercially viable?

This doesn’t mean Zeng is against solid-state technology but rather quite the opposite, as demonstrated by the significant investment he dedicates to the process every single day. Still, he warns that this product isn’t the commercially viable silver bullet it’s been made out to be. To spice it up, Zeng suggests shifting the discussion elsewhere, mentioning that sodium-ion battery technology could emerge as a more than viable alternative, as will be explained later on.

Several Automakers Are Determined To Make Solid-State Batteries Work

As mentioned earlier, there are several automakers that have decided to place their bets on solid-state batteries, with Toyota leading the charge. Criticized for its slow introduction of battery-electric vehicles compared to rivals, the Japanese giant only released its first electric vehicle, the Toyota BZ4X SUV, which uses lithium-ion batteries made by CATL, in February 2024.

Toyota Teamed Up With Idemitsu Kosan To Develop Solid-State Tech

While Toyota initially partnered with CATL in 2019 for its initial lithium-ion batteries, it later confirmed a collaboration with Japanese oil and petroleum company, Idemitsu Kosan, to heavily advance solid-state technology, for which they have already amassed over 1,300 patents.

Despite various lingering issues hindering the proper application of these batteries in cars, Toyota’s solid-state batteries are anticipated to debut in 2027, with mass production potentially taking place in India as the nation aims to assert itself as a global force in the EV transition process. Vikram Gulati, head of Toyota Kirloskar Motor, confirmed these plans at an investment summit in India.

Although Toyota asserts that its solid-state batteries could be a game-changer, pledging to enhance the range and charging numbers while also reducing costs, they are not projected to hit the market until 2027 at the earliest. By then, several other companies may have already introduced similar technologies, placing Toyota further behind than what they already are due to its delayed market entry. Other automakers heavily committed to solid-state technology include BMW, which is expected to produce its first solid-state prototypes this year, as well as Nissan, Honda, Ford, and Volkswagen.

Solid Electrolyte Instability: A Hurdle to Overcome

To complement Dr. Robin Zeng’s comments, there are several aspects that nobody is telling you about the solid-state batteries that currently prevent their widespread commercial application.

The transition from liquid electrolytes in lithium-ion batteries to solid electrolytes presents many challenges as solid electrolytes often exhibit poor stability, and their high surface resistance limits their output and potential applications. The exact mechanism behind the surface resistance in these batteries remains unknown to researchers and is linked to a phenomenon known as the Electric Double Layer (EDL), an effect that occurs at the interface between the solid electrolyte and the solid material, a complication absent in liquid chemistry batteries.

The unpredictable nature of the EDL effect is a significant reason why solid-state batteries are not yet available in today’s EVs. However, researchers and automakers remain optimistic, and with the increasing resources dedicated to research, it seems plausible that the breakthroughs needed for solid-state batteries will occur in the upcoming years.

Sodium-Ion Batteries Emerge As A Strong Alternative For The Upcoming Decades

Rather than looking at solid-state tech as the next major step forward, Zeng believes sodium-ion batteries, also known as “semi-solid” batteries, are where our focus should be. CATL has been actively researching them since 2021 as the next big thing in electric car development, so there’s clearly an interest for Zeng to advance with this if his company is the one pioneering the tech.

Sodium-Ion Batteries: Operational Principles

This type of rechargeable battery operates very similarly to lithium batteries, as the chemistry of the two elements is similar (both are alkaline), but instead the charge is carried using sodium ions (Na+) rather than lithium ions (Li+). While the operating efficiency is lower compared to lithium, sodium is extremely abundant in nature; it can be found, for example, in sea salt or in the Earth’s crust.

Advantages Of Sodium-Ion Batteries

• Abundant sodium resources: Sodium-ion batteries offer a versatile and economically viable option by relying on an alkaline metal so abundant on Earth and with relatively low production costs.
• Lower electrolyte concentration: Sodium-ion batteries can use lower electrolyte concentrations due to the characteristics of sodium salts, a cost-reducing factor.
• No alloy formation with aluminum: Sodium ions do not form alloys with aluminum, which allows the use of aluminum foil as a current collector. This further reduces costs by approximately 8% and lowers weight by about 10%.
• Less toxicity: They are less toxic than other popular batteries as they do not require lithium, cobalt, copper, or nickel, which can release polluting gases in the event of a fire.

Challenges Faced by Sodium-Ion Batteries

• Higher initial cost: Despite their performance, sodium batteries are relatively new on the commercial scene, therefore initially they will not be cheaper than lithium-ion batteries because the supply chain is still relatively small and less mature.
• Lower energy density: The average energy density of sodium-ion batteries ranges between 90 and 150 Wh/kg, which is lower than the 250 Wh/kg offered by lithium-ion batteries. This results in a higher weight for the same energy capacity.
• Development constraints: Sodium-ion batteries have been under development for many years, and while they offer advantages such as low cost and good performance at high and low temperatures, they still face a significant energy density gap compared to existing lithium-ion batteries, a factor that makes them a less desirable investment.

According to Zeng, this chemistry has the potential to double the range of lithium-ion batteries, which also aligns with what is stated about solid-state batteries.

Hydrogen Fuel Cells Are Gaining Traction As A Solid Option

The advancement of cleaner technologies knows no bounds, and that’s why there’s another option gaining significant recognition. Hydrogen fuel cells emerge as a renewable energy source with the potential to completely revolutionize how we generate power and fuel our transportation. By harnessing the chemical energy stored in hydrogen gas, these cells can convert it into electrical energy without producing harmful emissions or pollutants, making them a clean and environmentally friendly alternative to traditional fossil fuels.

The basic operating principle of a hydrogen fuel cell is simple. Hydrogen gas is split into protons and electrons, which then travel through an electrolyte and an external circuit to generate an electric current. This process is electrochemical, meaning it involves the transfer of electrons through a chemical reaction. While this is the simplest explanation, there are many types of fuel cells with slightly different functioning processes with the potential to be applied to mainstream cars.

Key Barriers Experienced by Hydrogen-Powered Cars

The main fact here is that, unlike traditional fossil fuels, hydrogen fuel cells emit no greenhouse gases when generating electricity. Still, it is crucial to assess the environmental impact of hydrogen fuel cell technology, as well as the cost and infrastructure challenges that lie ahead.

• Production method: The production of hydrogen which, by the way, is not naturally found on Earth, currently heavily relies on fossil fuels such as natural gas or coal. This undermines its primary purpose of reducing carbon emissions, as it shifts emissions from one source to another. To achieve a sustainable energy system, it is necessary to focus on developing renewable sources for hydrogen production, such as electrolysis powered by renewable energy sources like solar or wind.
• Production cost: One of the main drawbacks of hydrogen fuel cells is their high manufacturing cost, making them more expensive than other energy sources. The complex production process and the need for rare materials contribute to these high costs, resulting in higher prices for hydrogen fuel cell vehicles. This makes them less accessible to the average consumer, as they tend to have a higher price tag than both conventional combustion engines or battery-powered electric cars.
• Infrastructure development: Another challenge is the establishment of refueling stations where vehicles can replenish their hydrogen fuel supply. Unlike gasoline or electric charging stations, hydrogen refueling infrastructure is still scarce and concentrated in specific regions (in the United States, that would be California). The lack of infrastructure limits the practicality and convenience of owning a hydrogen-powered vehicle, as drivers may struggle to find nearby refueling stations during their journeys.

As you can see, transitioning to other types of vehicles is quite complicated and still evokes some insecurity since gas-powered cars have been the norm for many years. Therefore, making that change can be somewhat unintuitive.

However, we shouldn’t completely dismiss these possibilities. We need to observe how this impacts the automotive industry and how it makes us feel when getting into the car. It may surprise us, or it may disappoint us, but what is certain is that it should be your call, as you surely have your own take on this topic.