Safer and more durable than their lithium ion counterparts, solid-state batteries could be the next big thing in EV development
1 July 2019

Enthusiasm for BEVs (battery-electric cars) is growing, which is a good thing. That said, no amount of EV enthusiasts telling consumers they don’t actually need the range they think they do will convince them to pay more for something that does less. Manufacturers know this, which is why there’s so much talk surrounding the latest wonder-tech looming over the horizon: the solid-state battery

So what are these miraculous things that it’s claimed will banish any quibbling about range forever? The main components in any battery are electrodes (anode and a cathode) immersed in electrolyte. A conventional 12V lead-acid car battery contains a solution of sulphuric acid as electrolyte, which is fine as long as it stays in the battery. A lithium ion car battery has an inflammable electrolyte composed of lithium salts in a solvent. Lithium ion batteries have a further important component, too – the separator that keeps the electrodes apart. 

If lithium ion batteries are not carefully controlled when in use, then heat build-up can cause ‘thermal runaway’ resulting in a nasty chemical fire that is impossible to put out. Because of that they need complex electronic battery management systems and equally fiddly cooling circuits to keep them safe, making manufacturing harder and piling on weight and cost. The upside is that lithium ion batteries are more powerful and store more energy than any other battery type. But they could be better still. 

Solid-state batteries should overcome all those problems by switching to a non-flammable solid electrolyte, hence the name. Heat in a solid-state battery is easier to control so cooling is simpler, cheaper and less bulky, there’s no need for separators and a heavy, protective outer casing is unnecessary because the technology is intrinsically safe. The real barrier to getting them to work in the past was the poor conductivity of the solid electrolyte such as a ceramic material, but the latest materials are said by battery developers to be highly conductive. 

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The biggest bonus, though, is the energy density – the amount of energy a battery can store relative to its weight and volume. Claims for batteries capable of storing more than twice the energy of a conventional lithium ion battery are being made, along with reduced manufacturing costs. This simply means a solid-state battery will last longer and give an EV a greater range than a conventional battery of the same volume and weight. It’s that virtuous circle again. The lighter the battery, the lighter the car, the less energy it needs to achieve the same range, so the battery can be even smaller. 

Car makers are talking about the technology being in production by 2025 and some sooner than that. When and if it happens, it would radically change the automotive landscape. Radically increased range would reduce the need for charging on the move, easing the pressure on infrastructure, because one overnight charge (for those with such access) could make the need to charge during a longer journey less necessary than it is today. 

Inside a lithium ion battery

When the battery is connected to the device it is powering, like a motor, phone or whatever, ions are released from the negative anode to the positive cathode. When the battery is connected to the charger, the opposite happens and the battery is recharged.

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Comments
20

1 July 2019
It'll be the tipping point that EV manufacturers and the eco brigade have been waiting for.
Now all we need is a dozen nuclear power stations flinging up.

1 July 2019
No, we don't. Most ev owners charge at night when demand is low. Also, they don't need to charge every night.

1 July 2019

Under the headline it states, " solid state batteries could be the next big thing", followed by talk of "miraculous things"? Has he been living under a rock? Is he a serious automotive journalist appraised of the current developments in EV'S? If this is the best Autocar can wheel out, then the 'World's Oldest Car Magazine' is sadly doomed.

1 July 2019

Not wishing to be pedantic, but no one can be "appraised" of anything - the word you're looking for is apprised.

TBC

1 July 2019

A big question for the current users of EVs is, when this new battery tech is introduced, what will happen to the resale value of their lithium battery powered vehicle?

1 July 2019
TBC wrote:

A big question for the current users of EVs is, when this new battery tech is introduced, what will happen to the resale value of their lithium battery powered vehicle?

I would NEVER buy a second-hand EV.

1 July 2019

A BEV always seemed quite attractive to me but the thought of possible thermal runaway and nasty fires really puts me off.  Weren't there several instances of Teslas catching fire, along with lithium ion batteries in Sony laptops and Boeing Dreamliner aircraft?  I never leave my phone or camera battery unattended while they are charging.  I think I'll wait until this solid state technology actually happens, whenever that will be.

1 July 2019
streaky wrote:

A BEV always seemed quite attractive to me but the thought of possible thermal runaway and nasty fires really puts me off.  Weren't there several instances of Teslas catching fire, along with lithium ion batteries in Sony laptops and Boeing Dreamliner aircraft?  I never leave my phone or camera battery unattended while they are charging.  I think I'll wait until this solid state technology actually happens, whenever that will be.

How about fires in ICE cars? Statistically you are much more likely to catch fire in ICE but it does not make headlines because ICE car catching fire occassionally is sort of obvious. Also, battery fire is not as sudden as tank of fuel blowing up with Teslas usually giving passengers more time to leave the vehicle.
Also, apart from Tesla, other EVs do not seem to suffer from battery fires.

1 July 2019
TBC wrote:

A big question for the current users of EVs is, when this new battery tech is introduced, what will happen to the resale value of their lithium battery powered vehicle?

What can happen? Most expected old evs to drop in value one new generation with longer range arrives. The opposite happened as the awareness grew. Old evs will still offer the same savings as driving on electricity is cheaper.

1 July 2019

Musk has made a couple of comments about this and has mentioned that Tesla's so called skunk works are working on both solid state and ultra capacitors but has recently clamed up about them when asked about progress

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