There are two things electric vehicle manufacturers want — batteries that cost less, and batteries with higher energy density. (It would be nice if they didn’t tend to catch fire, too.) Unfortunately, those two goals are pretty much mutually exclusive. Lithium iron phosphate batteries cost less, but have relatively low energy density. Conventional lithium-ion batteries that include cobalt, nickel, or other minerals have the highest available energy density, but are expensive. The market is starting to diverge, with the more costly batteries going into high-end cars and those that cost less being used to power less expensive models.
The thing to keep in mind is that battery research is going on in laboratories around the world. There are lots of possibilities being explored, but none have reached the point where they are ready for production in commercial quantities. Another factor to keep in mind is that battery manufacturers have invested billions in the equipment that makes battery cells. Any new technology that cannot utilize the existing production process is going to get a chilly reception from the industry.
Sodium-ion batteries have been around almost as long as lithium-ion batteries. Sodium is 300 times more abundant than lithium, which makes it far less expensive, but early sodium-ion batteries had low energy density and a short lifespan. Lithium-ion became the darling of the energy storage industry and sodium was relegated to the backwaters of battery research.
But things are changing. In July of this year, CATL announced it had developed sodium-ion battery cells with an energy density of 160 Wh/kg. The best lithium-ion cells can store 240 Wh/kg, but LFP cells are close to that 160 Wh/kg figure. CATL says it plans to get the energy density of its sodium batteries up to 200 Wh/kg by the time production begins in 2023. In August, China’s Ministry of Industry and Information Technology said it would prioritize the development, standardization, and commercialization of sodium-ion technology.
Sodium batteries promise to have a longer useful life and faster charging times that other batteries, according to the Washington Post, which claims they could be 30 to 50% less expensive than today’s battery cells. Let’s think about that for a moment. Cheaper, longer lasting, fast charging, adequate energy density — what’s not to like? They may not be used in a Tesla Model S Plaid, but they could find a home in vehicles priced to sell for under $20,000. Which would you rather have, a few hundred Model S Plaids scattered around the world, or several million low cost, highly efficient electric cars?
Lithium-sulfur batteries have an energy density of up to 600 Wh/kg — more than double the best available lithium-ion batteries. Imagine what that could mean. Cars with 800 miles of range or more would be possible. That’s good. But Li-S batteries tend to eat their electrodes. That’s bad.
Researchers at the Monash University in Melbourne, Australia think they have solved the problem by adding a tiny dose of sugar to the formula used to make the electrodes for Li-S batteries. “In less than a decade, this technology could lead to vehicles, including electric buses and trucks, that can travel from Melbourne to Sydney without recharging. It could also enable innovation in delivery and agricultural drones where light weight is paramount,” Professor Mainak Majumder tells The Driven. The research has been published recently in the journal Nature Communications. The researchers found adding glucose, sourced from sugar, protects the electrodes against contamination from the sulfur compounds within the battery.
Sometimes science can find inspiration in the past. The researchers say that they were influenced by a geochemistry report published in 1988 which described now sugar-based substances had the ability to resist degradation in sediments when they formed chemical bonds with sulfides. They have tested new Li-S battery prototypes and found they managed to outperform lithium-ion equivalents for at least 1,000 charge/discharge cycles.
“Each charge lasts longer, extending the battery’s life,” first author Yingyi Huang says. “And manufacturing the batteries doesn’t require exotic, toxic, and expensive materials.” Co-author Mahdokht Shaibani adds that key challenges remain which need to be overcome before Li-S batteries enter commercial production. “While many of the challenges on the cathode side of the battery has been solved by our team, there is still need for further innovation into the protection of the lithium metal anode to enable large scale uptake of this promising technology — innovations that may be right around the corner.”
The research has been supported by the Australian subsidiary of the Thailand-based Enserv Group, which hopes to eventually manufacturer the lithium-sulfur batteries in Australia. “We would be looking to use the technology to enter the growing market for electric vehicles and electronic devices,” says Mark Gustowski, the managing director of Enserv Australia. “We plan to make the first lithium-sulfur batteries in Australia using Australian lithium within about five years.”
Anodes From Food Waste
Researchers at Virginia Tech say they have found a way to make battery anodes from food waste. “This research could be a piece of the puzzle in solving the sustainable energy problems for rechargeable batteries,” says Haibo Huang, an associate professor in the department of food science and technology in VT’s College of Agriculture and Life Sciences. “Demand for these reusable batteries has skyrocketed and we need to find a way to reduce the environmental impacts of batteries.”
Based on the preliminary results, the researchers found that the fiber component in food waste was the key to develop an advanced carbon materials that could be used as a battery anode, the negative terminal on a battery. “Our unique approach of using agricultural waste-derived carbon materials to host alkali metal, such as lithium and sodium, will bring major advances to agricultural waste processing and battery technology,” says Professor Feng Lin, according to a report by Technology Networks.
The two researchers got the idea to use food waste while playing basketball. “We thought why not convert food waste into battery materials because of how much food waste there is across the globe,” Huang says. “Most of these wastes are put into garbage and then sent to landfills. We just need to solve the battery side. As a food processing engineer, I can modify the composition of the food. I could take the proteins and lipids out, along with some of the minerals, to see how it impacts battery performance.”
They tested different types of food wastes to see if any could be used successfully to make batteries. They found that when certain compounds were removed from the equation, the essential compounds of cellulose, hemi-celluloses, and lignin could work for a battery after they were heat treated.
The anticipated initial uses of the technology are for affordable energy storage solutions for data centers or other large energy storage facilities where the size of the battery is not a factor. Their research will focus on reducing the impurities in the carbon that currently results from the process they invented.
“We have the opportunity to solve two urgent issues in two different industries,” Huang says. “A lot of energy is already put into the production and transportation of food in the food supply chain. We must recover the value from food waste. This is the perfect opportunity, as battery production looks for different materials than the traditional carbon.”
And Then There Is Toyota
Finally in today’s compendium of battery news comes word that Toyota has decided to invest heavily in battery technology and production. We know Toyota has its eye on solid state batteries — as does virtually every other automaker in the world. Solid state batteries replace the semi-liquid paste that actually stores electrons with a pliable polymer. The result is a battery that is less prone to the overheating that can lead to fires, as well as improvements in charging performance and battery life. But the technology is not quite there yet, although companies like QuantumScape, StoreDot, and Sakti3 believe they are close.
According to The Verge, Toyota announced this week it will invest $13.6 billion to create 10 battery production lines by 2025. Eventually, the company says it may have as many as 70 battery manufacturing facilities around the world that could produce 200 GWh of batteries annually. To put that in perspective, Volkswagen and Ford both expect battery production for their electric vehicles will hit 240 GWh per year by 2030.
Toyota hopes that its investments can help to reduce the cost of batteries by 30% thanks to improvements in materials and cell designs. It also plans to make electric cars that are more efficient, resulting in 30% less energy consumed per kilometer. “Through this integrated development of vehicles and batteries, we aim to reduce the battery cost per vehicle by 50 percent compared to the Toyota BZ4X in the second half of the 2020s,” says Masahiko Maeda, the company’s chief technology officer.
Is this a sign that mighty Toyota has finally given up on hydrogen fuel cell technology for its passenger cars? Let’s hope so, although a certain animosity toward electric cars permeates the company from the office of CEO Akio Toyoda on down. Recently, Toyota has been accused of employing lobbyists to delay or derail President Joe Biden’s electric car initiative.
The world of battery technology is changing so fast, it’s hard to keep up with all the latest news. The only question is whether cheaper, longer lasting, faster charging batteries will reach the market in time to turbocharge the EV revolution. It’s too late to talk about new technology that may be available in 10 or 15 years. The world needs electric vehicles now.
One interesting question is what will happen to fossil fuel companies as more electric cars take to the road? We reported recently that EVs displaced half a billion gallons of gasoline in the US last year. That, folks, is a lot of gasoline, and it bodes ill for the industry and the news is going to get worse as Ford and GM stand on the brink of bringing new electric cars and trucks to market. The pace of innovation is rapid and picking up speed. The golden age of electric transportation is just around the corner and getting closer every day.