Electric dreams

It’s myth-busting time, science-style. With more electric cars hitting our roads than ever before, questions are flying about their safety and sustainability. Do their batteries explode? Are they really better for the environment than diesel cars? And can you take them on a good old-fashioned Australian road trip? Let’s find out what’s fact and what’s fiction.

Do electric car batteries explode?

As electric vehicles (EVs) become more common, they’re raising plenty of questions and generating a few rumours – such as whether their batteries could catch fire or even explode.

Let’s go back a bit. How do batteries actually work? Batteries perform a chemical reaction which releases energy in the form of electrons – or stores energy by putting electrons back in. The electrons flow through a circuit, allowing electricity to power your machine. But something else has to move through the battery to balance the electrons zooming through the circuit.

An EV battery uses lithium to do this job, which can store more energy by weight than many other materials (such as the lead used in a lead-acid battery). In cars, energy density is extra important – both so you’re not lugging around too much weight, and so you can still fit a passenger or three in the car with you.

But lithium has its problems, including thermal runaway. The chemical reactions inside the battery, which make it work, can get out of hand, causing localised heating that can trigger a more significant event – such as catching fire.

However, it doesn’t happen all that often, according to firefighter Emma Sutcliffe from EV FireSafe.

“It’s a bit of a myth doing the rounds on social media that electric vehicles catch fire all the time,” she says. “In fact, they’re far less likely to catch fire than an internal combustion engine vehicle.”

There’s around a 0.0012% chance of a passenger EV battery catching fire. Internal combustion vehicles, on the other hand, have a 0.1% chance – 100 times more likely than an electric car.

Sutcliffe says that we have only had seven electric vehicle battery fires in Australia: “None have been spontaneous. There has always been human involvement to cause abuse to cells leading to thermal runaway and fire.”

But another explosive battery-powered device has flown under the radar.

“Unfortunately, in the last 18 months that we’ve been tracking this data … we’ve lost four whole families [globally] due to e-bike battery fires,” Sutcliffe says. “Poor quality e-bike batteries [are] catching fire in people’s homes, going into thermal runaway.”

E-bikes and e-scooters don’t have to adhere to any particular standards, she explains, while EVs must be road registered and comply with regulations and testing.

For example, if you’re in an accident the cage surrounding the battery in electric cars is built to take a beating. Plus in some EVs the battery is built to fall out of the car if thermal runaway starts happening.

Will electric cars ruin the weekend?

“I tell you what, it’s not gonna tow your trailer, it’s not going to tow your boat, it’s not going to get you out to your favourite camping spot with your family.”

According to former Prime Minister Scott Morrison in 2019, EVs would “end the weekend”. Is he right? To find out, we’re going to have to understand some EV specs.

“Even going across the Nullarbor is possible, if you factor in an extra day or two for charging time.”

Let’s start with torque. When you tap the accelerator in your EV, electricity from the battery flows to the motor, where it generates a magnetic field that turns a central rotor, thus turning the driveshaft. This forms part of the EV’s drivetrain – usually a single gear – which drives the wheels. The force causing the rotor to spin is called torque, and EVs have plenty of it. Torque is generated instantaneously and is consistent irrespective of rpm, which means EVs can do away with the need for multiple gears and revving up a big engine.

EVs have a high torque and power capacity, much more than most internal combustion vehicles. This is because EVs are efficient – around 80% of the energy stored in the battery is actually translated into the movement of the wheels, while the best combustion engine gets about 30% efficiency.

This means these cars are easily capable of pulling a heavy trailer. And as companies are redesigning the vehicle from scratch around an electric motor to make EVs even more efficient, we’ll see more improvements in towing capacity and torque.

What about range? The few dozen electric vehicles on the market today have fully-charged range estimates spanning from 400 to 600 kilometres. If you’re going to a major country town for the weekend, there’s no problem – chargers are being added to the network all the time, included ultra-rapid ones. Unless you’re going a long way off the grid, you’ll be fine. Even going across the Nullarbor is possible, if you take an extra day or two.

Four years on from Scott Morrison’s comments, the world of EVs is very different. The increase in charging infrastructure means you can make long trips across state borders with relative ease, as long as you plan your stops a little more carefully.

Still, a 45-minute charge gives a good opportunity to stretch the legs and grab a lamington.

Are electric cars actually more sustainable?

Some claim that if you’re not running an EV on renewable electricity, they’re worse for the environment than petrol and diesel cars.

Let’s see if there’s any weight to the rumour. You might assume that if you’re running an electric vehicle on grid electricity, it’s only going to be as clean as the grid it’s running from. Given that the majority of Australia’s electricity still comes from fossil fuel sources, what does that mean for vehicle-linked emissions?

Well, they’re still lower in most situations, according to Jennifer Rayner, head of advocacy at the Climate Council.

“There’s research that indicates that even if you’re powering an EV from the grid, which might be using a mix of power sources, that is still significantly cleaner than driving a petrol car, which is spewing out the emissions associated with its internal combustion engine,” she says.

Rayner cites the International Council on Clean Transportation’s assessment of vehicle lifecycles, which found that EVs have “by far” the lowest life-cycle greenhouse gas emissions. In the US and Europe, EVs were 60–70% cleaner than comparable conventional cars, while in India and China, with more coal-dependent grids, they were 19–34% and 37–45% cleaner, respectively.

It’s also worth noting that all of these statistics are changing fast – particularly in Australia.

“At the moment, we’re basically literally seeing the grid get cleaner by the day,” says Rayner.

In 2022, 32% of Australia’s total energy was generated from renewables, up from 29% in 2021. Renewable energy varies significantly by state: Tasmania and the ACT ran on 100% renewables (or close to it), while only 6% of the NT’s energy mix was renewable.

What about other emissions associated with electric vehicles? “It’s absolutely true that the production process for manufacturing EVs mean that it can produce something like 80% more emissions in the manufacturing process than an equivalent petrol car,” says Rayner.

Those extra emissions come primarily from the battery, made from precious metals like lithium, nickel and cobalt that take energy to mine.

“But over the lifecycle of a vehicle, the vast majority of the emissions come from driving it around,” says Rayner – and EVs win on that front, even when charging off a grid that is still reliant on coal and gas.

But drastically reducing transport emissions doesn’t need to involve cars at all. “To cut emissions by 75% by 2030 … we’d need to roughly halve the number of trips that Australians make by car and see a massive uptake in active transport,” Rayner says.

Can electric vehicle batteries be recycled?

Just 10% of Australia’s lithium-ion batteries were recycled in 2021, compared with 95% of lead-acid car batteries. But we’re going to have many more batteries to deal with over the next decade. Experts estimate we will have 1.6 million tonnes of EV batteries to recycle in Australia by 2050.

So how easy are EV batteries to recycle? Let’s start small. Don’t do this at home, but imagine you cut open a lithium rechargable AA battery. Inside you’ll see a mix of lithium, nickel, cobalt and manganese – all valuable and often rare materials. This little battery we’ve just mangled is called a cell.

EV batteries are made of the same components, but they’re slightly more complicated in structure.

“You won’t have just thousands of cells floating around – you might have them subdivided into packs,” says Katharine Hole, CEO of the Australian Battery Recycling Initiative. “Between those packs, you might have electronics, or a battery management system – they all monitor things like temperature or faulty cells.”

But they can still be recycled, just like smaller batteries.

“The processes we use to recover the minerals out of a battery are exactly the same as recovering a mineral out of the rock,” says Hole.

Small lithium batteries are “just put through a big shredding machine”, which produces a black mass from which individual elements can be separated. Two processes are used: hydro­metallurgy uses a series of chemical solutions to extract each of the metals, while pyrometallurgy uses high temperatures to do the same.

“If you’re not running an EV on renewable electricity, are they worse for the environment than petrol and diesel cars?”

Bigger EV big batteries can’t go straight into a shredder: they need to be disassembled, separating the casing and electronics from the cells, with each going down different recycling routes.

But there are some challenges to EV battery recycling, especially if the battery is damaged from an accident. Hole says there’s research into using robotics and artificial intelligence for the “safe disassembly, because clearly you’re dealing with batteries with very high voltages”.

EV batteries also don’t have to go straight to the shredder: they could be used in other applications, such as home battery storage, once they’ve run down too much to be usable in cars.