Batteries for EVs have progressed being expensive and while delivering impractical range, to less expensive and with just acceptable range, but only now showing signs they can soon enable price completive EVs with range that inspires confidence.
- The Benefits of Batteries/Recharging.
- Battery Theory.
- Terminology: Cathode, Anode, Electrode etc.
- Charge Time.
- Battery Life.
- Battery Technologies.
What do I mean ‘Battery’?
I use the term battery to mean something acts as storage of electrical energy, and although I rarely state ‘rechargeable battery’ I when I use the term ‘battery’, it can be taken to mean ‘rechargeable battery’.
The term ‘battery’ has evolved over time, and my interpretation is that mobile phones and electric vehicles have made rechargeable batteries so common that we no longer need bother saying ‘rechargeable’ depending on the context.
The original electric batteries were called ‘batteries’ because they had a ‘number of similar articles’ where each article was an electrical cell. But now we even have single cell batteries, which given that ‘battery’ originally meant ‘a number of similar articles‘, is a little contradictory. Meanings change, and the meaning of ‘battery’ is still evolving. The word ‘battery’ still can be used for a ‘battery of guns’ or a ‘battery of tests’ or batteries of other things, but without the ‘of something’ we now take ‘battery’ to mean storage of electricity.
Some people feel it is only a battery if the energy is stored internally as one or more chemical ‘cells’, but I would argue that it does not matter how the electrical energy is stored, to most people it is battery because of the function, not how it achieves that function. So in general use, anything that holds energy for later use as electricity, can be considered a battery. So even a capacitor can be considered a battery.
Single Use vs Rechargeable Batteries: For Vehicles, ‘battery’ means ‘rechargeable’.
Depending on context, the term ‘battery’ can be assumed to means ‘single use battery’ or ‘rechargeable battery’. If someone says “do you have AA batteries”, single use batteries are usually assumed unless it is specifically stated that the batteries are ‘rechargeable’. However, with mobile phones, automobiles and battery electric vehicles, battery is assumed to be ‘rechargeable’. We never say ‘rechargeable car battery’, or ‘rechargeable mobile phone battery’ because these batteries are always assumed to be ‘rechargeable’ batteries.
On this page, and all pages related to EVs, ‘battery’ is taken to mean ‘rechargeable battery’ unless specifically stated otherwise. In many ways, single use batteries have more in common with gasoline as as source of energy than with rechargeable batteries. With both gasoline and single use batteries, energy supplies are replenished by adding a new supply of the original chemicals.when energy runs low, more chemicals pred The comments here apply to specifically to rechargeable batteries, although as EV batteries are
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Batteries and the Price of Electric Vehicles.
There was a time when computers less powerful than what is today a low priced home computer filled rooms, cost millions of dollars and were something normal people imagined having at home. There was a time in the 1980s and early 1990s when mobile phones could cost $4,000 or $5,000 and normal people did not imagine ever owning one.
The bad news is electric vehicles are not about to go through that type of price crash. Just the batteries, which in a 2021 EV is around 50% of the price.
The power for all current engines always comes from chemical energy.
All current vehicles are powered by chemical reactions. Internal combustion engines are powered by the heat from a chemical reaction between gasoline/petrol or diesel or hydrogen with oxygen, and electric vehicles are powered by electricity generated by a reaction between the chemicals inside the battery, or for hydrogen fuel cell vehicles, the chemical reaction between hydrogen and oxygen to produce electricity.
Rechargeable Gasoline, Refuellable Lithium: Both Technically Possible.
In a gasoline engine, the main chemical reaction is:
gasoline + oxygen -> CO2 + Water + energy(heat)
While there are some ‘burnt impurities’, and the heat is so intense that some nitrogen is also burnt, the components listed above are those that are needed for the engine to work.
In theory, if the tailpipe emissions of CO2 and water were retained, then instead of refuelling it would possible to run add heat back into the ingredients, and thus run the equation in reverse:
CO2 + Water + energy -> gasoline + oxygen
This would result in a sustainable internal combustion engine vehicle. Of course, there are some problems. This is not an easy reaction to run in reverse, and as internal combustion engines are so inefficient there is a lot of energy needed to reverse that reaction. But if we could add a ‘recharger’ that took the emissions from an internal combustion engine, and a source of heat from a recharging station, we would mimic many of the important qualities of an electric vehicle. Also, instead of needing the exact right fuel, the heat could be generated however we want, as heat is always heat.
Similarly, a lithium iron battery also runs a chemical reaction, only this is two half reactions at each side of the battery:
1) LiCoO2 -> CoO2 + Li+ + e-(electrical energy) 2) Li+ + 6C + e- -> LiC6
Where the Li+ electrolyte is in a solvent that can flow between cathode and anode. You will often see these formulas with a bi-directional arrow, because taking the electrical energy out makes the reaction go one way (discharge), but adding the electricity back makes the reaction goes the other way (recharge). At ‘recharge time’, instead of putting electrical energy back, it is technically possible to simply take out the CoO2 (Cobalt dioxide) and LiC6 (lithium graphite) as exhaust, refresh the electrolyte, and put in new LiCo2 (lithium cobalt dioxide) and C (graphite), replacing the chemicals as we are doing when refuelling a gasoline car. By replacing the chemicals, the car would be ready to go again without the time delay of recharging.
The problem with this is that for every battery chemistry, there are different chemicals, which would mean there would need to be range of ‘fuels’ even more diverse than the different octane ratings we have for gasoline/petrol. Plus, not everything is in the convenient liquid form.
In the end, there are good reasons why no one is going to actually recharge a gasoline fuelled vehicle with heat, and nor is anyone going to refill the chemicals for a battery vehicle, but contemplating what would be needed highlights the differences between the nature of the systems.
The approach with gasoline is to continually run chemical reactions with chemicals that are preloaded with energy (gasoline and oxygen), runs the reaction once and then discard results of the reaction as exhaust. The entire system was conceived at a time when the very concept of ‘renewable’ appeared unnecessary. The inputs are the specific chemicals required by the reaction.
The battery approach keeps the outputs of the reaction, and allows resetting everything back to the original conditions through the use of energy that itself can be renewable. For the life of the battery, the only input is energy.
The Benefits of Batteries.
Electric vs Chemical Input: Ultimate Flexibility.
Chemical (e.g. gasoline) Refuelling is inherently inflexible.
An combustion engine without a ‘recharging system’ which can return the ingredients to their original state, requires an exact ingredients the engine is designed around. Fortunately, of the two ingredients of a gasoline engine, the oxygen is readily available from the air. However gasoline (or diesel), must be mined and then refined to quite precise formulation required by the engine. Without gasoline, which is only available by way of one specific supply system, the engine cannot be used.
A battery vehicle can use any source for the energy. Not only is the mains electrical system that is normally used as the source of energy available at almost every dwelling in the developed world, it is also possible to provide energy from solar or wind. Even in the most remote location, it is possible to generate electricity from natural sources without any need to locate specific chemicals. With enough time people could even hand crank a small amount of electricity. This allows for vehicles such as the Aptera, or the Lightyear One, that can travel normal commuter distances each day on a days solar energy alone.
Since batteries are recharged by energy, rather than the chemicals inside the battery that react to produce the energy when it is needed, how the battery stores energy can change, with no impact on refuelling. The reactions above are for ‘conventional’ lithium-cobalt-graphite batteries that have been used in most mobile phones and electric vehicles so far, but already different battery chemistries are being introduced, with phosphorous having already replaced cobalt in BYD batteries, and also being introduced by Panasonic.
Supply Security and Sovereignty.
Moving from requiring one specific chemical formulation for fuel, to requiring electrical energy, is moving to almost total fexibilty.
While a specific chemical formulation can only be satisfied by obtaining that exact fuel, any form of energy can be converted into electrical energy.
You can source electrical energy from solar, or wind, or tidal forces, from hydro or from waves, as well as from any fossil fuel. Any of these sources and more can be used to produce electricity. If you have energy, you can produce electricity, while the gasoline or diesel required by an internal combustion engine can only be produced by an oil refinery, which in turn requires a specific resource which is far from universal and requires complex equipment to extract when it is found.
If society is without electricity, the ability to power vehicles is not the most immediate problem, and of this reason, solutions to problems in electricity supply are numerous and well tested. Any supply problems are will almost always be local, and with an EV, the vehicle may even be able to out and get more power and bring it home. With electricity, there is no need to be at the mercy of foreign states able to impact supply.
Under battery technologies below, there are several new products and their proposed timelines. However, this is not car companies announcing products. Those will appear here:
Tesla 4680 Battery.
Terminology: Cathode, Anode, Electrode etc..
A note on terminology as it can be confusing, particularly the terms ‘cathode’ and ‘anode’ when discussing rechargeable batteries. The cathode is the terminal from which current flows, and the anode is where the current arrives. Since currents flow in the opposite direction during use of battery power or ‘discharge’ than current flows during ‘recharge’, each physical part of a rechargeable battery swaps roles. So the cathode during use, becomes the anode during recharge. This causes much confusion, and I have seen several videos and sites that get confused by this and think one side of the battery is the ‘cathode’ and the other is the ‘anode’ at all times, not realising this changes. Also note to make things even more confusing, electrons flow in the opposite direction to current. For these reasons, I will stick to a simpler ‘positive electrode’ and ‘negative electrode’ in any explanations.
Chemical batteries are limited in the speed they can absorb charge, but recharge points are also limited in the speed they can supply charge. Fuel tanks for gasoline and diesel vehicles can absorb fuel ‘instantly’, but it still takes some time to refuel. This is because pumps only pump fuel at a finite speed. The flow.
For comparison consider diesel vehicles. There are special ‘high flow’ pumps for large trucks that can deliver fuel so fast that the fuel will go everywhere instead on just into the tank if these ‘high flow’ pumps are used with vehicles not specially designed. The tank can take fuel ‘instantly’, but the hose from the fuel filler to the tank can only manage a certain speed. Trucks can use a really big hose to handle a higher speed, but that is also limited by the maxium rate the fuel pump hose can handle. So there are three contraints:
- Gas/diesel pump speed.
- Hose from fuel filler point on car/truck to tank.
- Tank maximum fill speed (no problem with gasoline or diesel tanks)
With electrical vehicles, chemical batteries normally do have an effective limit on how fast ‘the tank can be filled’, but the other two limitations also apply:
- Charging Station maximum power rating.
- Car/truck connector and cabling to battery maximum power rating.
- Battery maximum ‘fill’ (recharge) speed.
This means that even with future battery technologies that do not limit battery recharge speed, refilling will still not be instant, just as refilling a large truck today is not instant. Currently the fastest chargers have a maximum power rating 350kw, so a 100kw/hr battery would need 100/350 hours or 17 minutes to recharge. The Hyundai Ioniq 5, one of the fastest charging vehicles of 2021, can recharge 75% of an 53kw/hr battery in 18 minutues, so just under half the maximum possible.
Battery charging could in future rival times for filling liquid fuelled vehicles, but they still wont be instant and it doesn’t just depend on the vehicle.
Batteries can be replaced, as shown on this video. While the battery structure with dedicated EVs is often currently integrated into the vehicle, and the replacement is specific to the vehicle, the process is simpler than replacing an engine in an internal combustion engine vehicle, and making 3rd party replacements should be easier.
One one hand, batteries are improving so rapidly including lifespan, that already we are seeing batteries that may outlast the normal life of a motor vehicle, but on the other hand, batteries are improving so rapidly that batteries also become obsolete before they will fail.
And as I said before, with batteries, it looks they’re going to start lasting way longer than the vehicles, which means you can amortize the cost of the battery over three vehicle lifetimes right, so where there were its going to land on batteries right now like no one has any idea. It’s really a strange time to be in this industry. And with the mineral resource issues and mining stories coming out about lithium extraction, your going to see more attention being put to battery technology. I think were going to see some interesting alternatives coming out here pretty quickly. Especially on the solid state side of things, you’re going to see some interesting breakthroughs.Aptera CTO Nathan Armstrong.
The off the cuff remarks quoted above convey the contradiction that while batteries may now last longer than the car, they may be the first part of the car to be out of date. Fortunately, replacing the batteries can be practical, and as batteries improve, replacing them can result in a vehicle that becomes even better than when new. When batteries are replaced, the materials are valuable and recycling is possible.
(this section still being updated)
The benefit of all batteries being charged by electricity and output electricity, is that how batteries work internally can be changed with no impact on the infrastructure to recharge. This means that what we have now is only a starting point, and there are many potential improvements to charging times, cost, lifespan, safety and environmental impact still to come.
If you had a million dollars to invest in a battery company, right like right now where would you put your money, right, like it’s changing so quickly and every six months there is a new technology it doesn’t quite make it to market but you know it threatens to kind of like you know change the whole industry again, um so battery technology is a really weird one, right, like we have these lithium cells so they’re pretty good um five years from now they’re going to be way better different chemistry 10 years from now something different again so we are trying to be king of battery agonistic.Aptera CTO Nathan Armstrong.
Despite first being developed back 1970, mass manufacture of lithium ion batteries is relatively recent. The first commercial battery products did not appear until 1991. If you are old enough to recall older mobile phones had first nickel cadmium batteries (invented in 1899), and then nickel metal hydride batteries, with both of these older battery types having a ‘memory effect’.
Cobalt Lithium Ion: Since 1970
Electric vehicles so far have mostly used lithium ion cobalt oxide ion batteries (LiCoO2) as described here and first developed in the 1970s. Lithium is highly reactive which would make significant amounts of pure lithium dangerous, so cobalt is combined with lithium to form LiCoO2 as a container to hold the lithium more safely in a less chemically active form. Cobalt is not rare, but cobalt in the form that is lowest cost to extract is found almost exclusively in the Congo, creating a supply chain risks, and at times as much of 10% of that Cobalt being mined, has been mined using unsafe practices. In batteries with cobalt, the cobalt becomes the main factor in the cost of the battery.
Phosphorous: In passenger EVs since 2020.
Lithium ion phosphate batteries (LiFePO4), are an alternative to using cobalt that reduces battery cost and results in a safer battery.
Historically, despite being less expensive and longer life, lithium ion phosphate batteries (LiFePO4) have had lower energy density than cobalt based batteries, which limited their use to busses and larger vehicles. However, several companies now have solutions to the energy density, which allows a price, safety and lifespan breakthrough from lithium phosphate batteries such as the BYD blade battery.
Graphene: Future (September 2021?).
Although originally observed in electron microscopes in 1962 as occurring on suppotive metal surfaces, graphene isolated and fully analysed for the first time in 2004 by Andre Geim and Konstantin Novoselov at the University of Manchester. This resulted in a Nobel Prize just 6 years later in 2010. Remember it took 16 years from Albert Einstein’s ‘miracle year’ of discoveries in 1905 to his Nobel prize in 1921, so it is clear this work was quickly recognised as a big deal.
Graphene based batteries hold promises of ‘instant charging’ combined with:
The rapid charging isn’t the only selling point. In the lab, NanoGraf says its graphene batteries show a 50 percent increase in run time compared to conventional lithium-ion ones, a 25 percent drop in carbon footprint, and half of weight needed to provide the same output.Futurism.com
To date, graphene is the strongest mineral ever discovered, with 40 times the strength of diamond. It is more effective as a conductor of heat and electricity than graphite. … Graphene is capable of transferring electricity 140 times faster than lithium, while being 100 times lighter than aluminium. This means it could increase the power density of a standard Li-ion battery by 45%.Mining Technology.
GAC, a subsidiary of Chinese state owned GAIC, has announced “The batteries will be installed in the first vehicle from September”, which would be the 1 year anniversary of the joint venture project with GAC and .
Solid State Batteries: Future (VW plans for 2024-2025)
Solid state batteries promise far higher energy density than current electrolyte lithium ion batteries, almost instant recharging, lower costs, and can be extremely durable. Some project it will take 10 years for them to take over, but a joint venture between VW group and QuantumScape plans for volume production by 2024-2025.
QuantumScape is developing what many consider the Holy Grail of electric car batteries: a highly-efficient, long-lasting, long-range, fast-charging electric car battery cell.
The battery startup achieves this by replacing* the liquid electrolyte that regulates the flow of current with a solid electrolyte.
The polymer separator used in conventional lithium-ion batteries is substituted with a solid-state ceramic separator, QuantumScape says. As a result, the less-efficient carbon or carbon-silicon anode is replaced with an anode of pure metallic lithium.Forbes: Feb 2021.
Aluminium ion and Graphene: Future (Coin cells 2021, Automotive 2024-2025).
Batteries do not have to use lithium as the electron donor metal. Lithium is the lightest metal, and with the smallest size atom, but lithium atoms only have a single outer shell electron per atom, and thus only allow a +1 charge. Aluminium, although a larger and heavier atom, has 3 outer shell electrons, not one, and this gives aluminium the potential for a +3 charge, which it turns out results in even greater energy density than with lithium.
There are a variety of projects to deliver aluminium batteries, eg:
GMG plans to bring graphene aluminum-ion coin cells to market late this year or early next year, with automotive pouch cells planned to roll out in early 2024.
Based on breakthrough technology from the University of Queensland’s (UQ) Australian Institute for Bioengineering and Nanotechnology, the battery cells use nanotechnology to insert aluminum atoms inside tiny perforations in graphene planes.
The GMG technology drops aluminum atoms into perforations in graphene.
The Graphene Manufacturing Group’s aluminum-ion technology can charge an iPhone in less than 10 … [+] GRAPHENE MANUFACTURING GROUP
Testing by peer-reviewed specialist publication Advanced Functional Materials publication concluded the cells had “outstanding high-rate performance (149 mAh g−1 at 5 A g−1), surpassing all previously reported AIB cathode materials”.Forbes: 2021 May 15 (worth reading the article)
Supercapacitors and Ultracapacitors. (nothing scheduled to replace batteries).
Capacitors could also be used as the ultimate ‘solid state’ battery, simply storing a charge using electrostatic attraction. Although there is significant work on supercapacitors for use in EVs, and supercapacitors do function in some ways like a battery, the role they are currently ‘auditioning for’ is to augment the ability of a battery a battery to deliver extremely high currents instantly. If instead of feeding motors directly from a battery, the battery feeds a capacitor that in turn feeds power to the motor, then the system can deliver brief periods of peak current beyond what the battery can deliver. This role, not of being the primary battery, is what is being proposed at this time.
Companies involved include SkeletonTech.
Al Air. (Nothing scheduled to replace rechargeable batteries)
In addition to Aluminium ion batteries where aluminium replaces the lithium, there are also aluminium air batteries. However, these batteries are, so far, not rechargeable and thus not a contender in the same way as other batteries technologies discussed here.
The battery journey is still at an early stage. Right now, the cost of batteries puts EVs at a cost disadvantage to conventional cars, but that disadvantage is evaporating rapidly as shown by the quite competitive F150 lightning recently announced. By 2025, there will be a cost competitive EV for almost all new vehicle market segments.
However, 2025 is not the end of the line. EVs will continue getting less expensive for years to come, just as PCs did for decades.