How Ford, GM and Tesla are building better EV batteries – Reuters

This story is part of Recode by Vox’s Technical support series, which explores solutions for our warming world.

When consumer lithium-ion batteries debuted in the 1990s, they were revolutionary: they recharged in hours or less and have made our modern computers and phones truly portable. But three decades later, this battery technology needs a major upgrade, because the harsh reality of climate change means that lithium-ion batteries not only need to power our devices, but also our cars. It is much more difficult.

Lithium-ion batteries have become the quintessential form of energy storage because they have extremely high energy density, which means they can store a lot of energy in a relatively small volume. Lithium itself is the the lightest metal in the periodic table, making lithium-ion batteries extremely portable. As technology has been incorporated into electric vehicles (EVs), these batteries have been pushed to their limits.

They can only be loaded and unloaded a certain number of times, and we may have reached the upper limit of their storage capacity. This is one of the biggest concerns people have with electric vehicles because more capacity equals longer range. Batteries also take up a lot of space in the cars we already have, which means we can’t just add more batteries to get more range.

So if this EV revolution is going to be successful, batteries have to get better. They need to go even further on a single charge and they need to weigh less. Electric vehicle batteries must also be less likely to ignite, a rare but very concerning problem. (Gasoline and hybrid cars are also fire hazards.) Chevy recently had to recall all Chevy Bolts it sold because of the battery fire hazard. Lithium-ion batteries in today’s cars could also benefit from new core components. They are currently made from rare materials, such as cobalt and nickel, which are increasingly expensive.

The race to solve these problems is accelerating. Longtime battery makers like CATL and LG Energy Solution are rethinking fundamental battery chemistry so they perform better in electric vehicles. Meanwhile, Ford and GM are investing in new battery research, hoping to have an edge over Tesla. Even the government is getting involved: In March, President Joe Biden invoked the Defense Production Act – a 1950 law that allows the president to boost domestic production of certain products in an emergency – to increase the supply of the country in rare metals and materials used in electric vehicles.

That’s fine, but time is running out. Climate change is only accelerating, and each new car running on fossil fuels risks exacerbating the threat. Fortunately, better battery technology isn’t just being developed; it’s starting to hit the market.

The lithium-ion battery, explained

Electric vehicles are not powered by one large battery, but rather by thousands of smaller cells. Each cell has four key components that make up a battery: an anode, a cathode, a separator, and an electrolyte, which is usually a liquid. To power a device like a car, charged atoms or molecules called ions move from anode to cathode through the electrolyte, releasing their extra electrons along the way and generating electricity. To charge a battery, the reverse happens: electrons flow through the battery and ions flow back from the cathode to the anode, creating potential energy that the battery can then discharge.

In the case of lithium-ion batteries, these ions are naturally lithium ions. Sony sold the first lithium-ion battery to power one of its camcorders, and battery technology quickly became ubiquitous in consumer electronics. Partly because they are now so widely available, automakers have turned to lithium-ion batteries to power their electric cars. They do this by typically packing dozens of lithium-ion battery cells into larger protective shells called modules. These modules are then assembled into an even larger battery, which powers the EV.

However, lithium-ion batteries aren’t exactly perfect for electric vehicles. Beyond the unlikely but real risk of igniting, the average EV has a range of 260 miles. That’s enough to get around for daily trips, but many drivers worry about longer-distance excursions.

Lithium itself also has some issues. Lithium mining is not particularly environmentally friendly, and currently the world does not have enough lithium mines to provide enough material for the number of electric vehicle batteries we have. probably need. There are also growing concerns about other metals commonly used in lithium-ion batteries, namely cobalt, which is mainly mined in the Democratic Republic of Congo and is linked to child labor and human rights.

New materials

A relatively simple way to build a better battery is to incorporate different materials into conventional lithium-ion technology. New materials come with their own pros and cons, and some combinations might be better for electric vehicles than others.

One such combination is called a lithium iron phosphate battery, which incorporates lower cost materials into the battery cathode. Although these batteries cannot hold as much energy as other lithium-ion batteries, they allow automakers to build more batteries for less money and, therefore, offer more electric vehicles at a lower price. lower. Lithium iron phosphate batteries are already widely used in China, and Tesla announced last fall that it would start using the chemistry in its standard-range vehicles.

Another approach changes the battery anode materials. Many lithium-ion batteries currently have graphite anodes because they are relatively cheap and last a long time. But a handful of startups are using silicon instead, the same material used to make computer chips. Batteries with silicon anodes can hold 10 times more charge than graphite anodes and increase the overall energy capacity of a battery. Companies like Sila Nanotechnologies, NEO Battery Materials and Enovix are currently perfecting their designs.

A solid idea

As the name suggests, a solid state battery uses a solid electrolyte instead of the traditional electrolyte. This solid material is not a giant block, but rather a layer of material like glass or ceramic. Solid electrolytes are more compact, which means solid-state batteries can be smaller and store more energy. Another advantage is that solid electrolytes are not as flammable as traditional lithium-ion batteries, nor do they require the same cooling infrastructure.

Solid-state batteries still face real hurdles. They’re expensive and difficult to mass-produce, so they’ve mostly appeared in labs so far. Another challenge is that many solid-state battery designs have a lithium metal anode, instead of graphite. This metallic lithium sometimes forms dendrites, branches of metal that leak from the anode and into the electrolyte, which can cause a solid-state battery to crack and short.

That doesn’t make these batteries a dead end. They’ve already been incorporated into some pacemakers, prototype headphones and other electronic devices, and now the auto giants are exploring how to tweak the technology so they can eventually work in cars as well. There are already encouraging signs of progress: Volkswagen, Ford and Stellantis have all invested in technology. Toyota plans to launch a hybrid vehicle that uses a solid-state battery by 2025, and Nissan hopes to launch an electric vehicle that uses solid-state batteries by 2028. Another company called QuantumScape has shared research suggesting that a solid-state battery can work – and charge faster than other batteries – when combined with another idea: a battery that doesn’t need an anode at all.

Car shaped batteries

Finally, lithium-ion batteries may not look like batteries at all. They might just become part of what they feed. This is the idea behind structural batteries, which would have a battery double as another part of a vehicle, like the body of a car or the fuselage of an airplane.

This could address a fundamental challenge with batteries, which is that they are incredibly large and heavy. Allowing a vehicle part to double as a power source could, theoretically, reduce the overall size of an electric vehicle. It would also mean, potentially, using fewer raw materials overall.

This concept is gradually being integrated into vehicles already in circulation. Tesla has designed a new structural battery that will attach directly to the seats inside of its Model Y vehicle. Similarly, Volvo plans to reduce the footprint of its batteries by designing them to also support the floor of their cars, and GM is already rolling out electric vehicles that use batteries to reinforce the chassis of their vehicles. These may seem like small tweaks at the moment, but they could pave the way for cars powered entirely by their own chassis, and maybe even planes.

The battery boom gets even bigger

Powering vehicles will be a Herculean task for batteries, but it won’t be the only one. In order to move away from fossil fuels, we need to use renewable energy sources, such as solar and wind power. But since the sun and the wind are not always present when we need electricity, we have to store the energy they provide when we need it. That means our homes, our cities, and even the power grid will need batteries, which are really, really big.

These batteries will not necessarily have the same needs as the batteries used in cars, just as the batteries we use for cars do not have the same needs as the batteries that power our phones. After all, a battery that stores power for your home doesn’t need to be particularly light — it won’t move — nor does it need to charge quickly. This means that these batteries will not necessarily need lithium and could even be powered by emerging alternatives, such as sodium and zinc. But while these individual batteries are not all the same, they will all play a vital role in powering the future and slowing climate change.

At least for now, anyway. It’s certainly possible that in the future we could power our cars with futuristic fuels, or maybe even portable nuclear reactors. But all signs indicate that these technologies won’t be ready anytime soon. For now, the battery is the best we have.

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