Technologies that will make electric vehicles even better
In 2010, when the first generation of mass-produced electric cars started to arrive, I felt that automakers were undermining electric cars on purpose.
Back then, most legacy automakers decided to use LMO battery cells with poor energy density and short cycle life in their electric cars. The biggest advantage of those cobalt-free battery cells was the lower cost, nonetheless the electric cars were being sold with a price three times higher than their gas-counterparts. Only Tesla went with high energy density battery cells, which at that time were available in the form of NCA cylindrical cells – mostly made for laptops.
Fast forward to today, now legacy automakers actually produce decent electric cars, but they could already be much better.
In this article I’ll sum up some already existing technologies that will soon make electric vehicles even better.
- 800-volt systems
- Silicon anodes
- Cobalt-free batteries
- CTP battery packs
- Solar roofs
- V2G and V2L
- Aerodynamic improvements
- Wireless charging
800-v systems – especially when combined with silicon-carbide (SiC) semiconductor power electronics – greatly improve electric powertrains, making them more efficient, smaller, lighter and cheaper.
Porsche, Hyundai and Kia are already producing electric cars with 800 volts electrical systems instead of the usual 400 volts. However, BYD will be the first automaker to make this technology available in affordable electric cars with the upcoming BYD EA1.
What makes 800-volt systems better than the usual 400 volts?
The latest results from research on 800-volt battery-driven vehicles show that this could lead to smaller, lighter, and more environmentally friendly motors. Cars using these powertrains could also be charged faster and travel further on a single charge.
One such advantage is that 800-volt electrical systems allow a greater retention of power, which is normally lost through heat generated during the charging process. A higher voltage system allows a lower current to be used when charging the battery, which reduces overheating and allows better power retention in the system. This power can be used towards a longer driving range.
Higher voltage systems also offer a number of key weight- and mass-saving advantages. The reduction of copper is one of these. Electric motors are much simpler than combustion engines in construction and at their core they have a rotor, which turns in response to a rotating magnetic field created by electricity from the battery. To achieve this, electrical systems often use up to four times the amount of copper found in combustion engines. Using higher-voltage systems can lead to the amount of copper used in motors being significantly cut.
Besides reducing the weight of motors, an 800-volt system has the added advantage of reducing their mass too. Since the higher voltage allows the motors to run at speeds of 20,000 rpm, well over double that of their 400-volt siblings, they have better power density. This means that they convert electrical power to mechanical power with this speed and not high torque. “In general, motor size is defined by torque capability,” Bitsche says, which means removing torque from the equation allows motors to be much smaller. So much, in fact, that smaller high-speed motors can weigh as little as 25 kilograms, with the result that they reduce the overall weight of a vehicle, enabling it to travel much further on a single charge.
Summing up, with 800-volt systems, electric cars will get more efficient, lighter, smaller and cheaper powertrains.
In the last few years, battery technology evolved mostly by introducing improvements to cathodes, while anodes remained almost the same. However, the next big evolution in battery technology will happen with the upcoming replacement of graphite anodes by silicon.
Battery cells with silicon anodes are more energy and power dense than their graphite counterparts. This battery technology goes hand-in-hand with 800-volt systems, since both are required for electric cars to achieve extremely fast charging rates.
Moreover, silicon anodes can also be used in battery cells with cobalt-free cathodes, such as LFP (LiFePO4) as Guoxuan already demonstrated.
Summing up, with silicon anodes, battery cells will increase their capacities and reduce their charging times.
Soon, cobalt-free batteries will become standard in electric cars, either with LFP or LNMO cathodes. While more expensive high-nickel content chemistries, such as NCM 90, NCA 91 or NCMA will be relegated to some niches, where getting the most range is important.
Thanks to cobalt-free batteries, electric vehicles will finally be able to compete with their ICE (Internal Combustion Engine) counterparts in price and availability.
CTP battery packs
CTP (cell-to-pack) batteries are module-less and go hand in hand with safe cobalt-free battery cells, such as LFP (LiFePO4).
While in most battery packs, having modules increase their safety by functioning as metal firewalls in case one or more NCM/NCA battery cells burn or explode, they serve no purpose when used with LFP battery cells, since these super-safe battery cells won’t catch fire or explode even if punctured.
One example of a good CTP battery is the popular BYD Blade battery, which has high VCTP (Volumetric cell-to-pack) and GCTP (Gravimetric cell-to-pack) ratios. This means that in the battery pack, the active material – that actually stores energy (battery cells) – is proportionally higher in terms of volume and weight than the passive material, that only serves to protect and assemble the battery cells.
By getting rid of modules, the VCTP ratio of a battery pack can increase from 40 to 60 %. With CTP, batteries become simpler, lighter, smaller and cheaper.
Electric cars with solar roofs are a no-brainer, especially now that solar cells have become more efficient and extremely cheap.
In some situations, a good 300 W solar panel roof in an electric car could add around 2 kWh to the battery per day and would be enough to drive an extra 10-15 km.
V2G and V2L
Solar roofs, V2G (vehicle to grid) and V2L (vehicle to load) are some technologies that could soon become standard in EVs. How cool is that you will be able to use your electric car as a large mobile power bank that can be charged with solar energy?
The EV6 is equipped with vehicle-to-load (V2L) function that works as a convenient, portable electricity supply for your daily life or leisure activities.
It can serve as an emergency power source for your home. In fact, EV6 supplies up to 3.6kW of electricity and it can also work as a portable generator when enjoying the outdoor activities.
Some examples where large mobile power banks can be useful:
- Vacation house in a remote area without access to the electrical grid
- Construction work in remote communities
- Farmers’ market
- Music festivals
- Emergencies during a power outage
- Charging other EV
We can increase the range of an electric car, either by adding more battery capacity or by increasing its efficiency.
While improving the powertrain or reducing the weight of the vehicle are valid methods to increase the overall efficiency of an electric car, the improvement in aerodynamics has the highest ROI (Return of Investment). Electric powertrains are already extremely efficient and thanks to regenerative braking, reducing the weight isn’t as important as improving the aerodynamics in an electric car.
Not all electric cars need to take aerodynamics as serious as the Lightyear One – that we see in the image above -, but it’s obvious that most electric cars still have a big room for improvement. Just look at current Volvo electric cars to see what I mean…
Besides the design of the vehicle itself, there are many cheap and easy ways to improve the aerodynamics of electric cars. Let’s see some examples below.
- Smaller wheels
- Aero wheel caps
- Fender skirts
- Flat underbodies
- Cameras instead of side mirrors
Not only is wireless charging essential for autonomous electric vehicles, it will also make the use of public charging infrastructure safer and more convenient. No more worrying about having the charging port or cables vandalized by some caveman that hates electric cars.
Autonomous electric vehicles are the future of personal mobility—but with no driver, who will plug in the vehicle to recharge it? The answer is clear: No plugs, no wires. Park-and-charge wirelessly and autonomously…with WiTricity technology.
We’re done for today, these are some technologies that already exist and have the potential of making electric vehicles even better.
While there isn’t an electric car with all the technologies listed above yet, I think that the upcoming BYD EA1 illustrates what a next generation electric car should be like and has the biggest potential to become a game changer. It’ll have a CTP cobalt-free battery and an efficient 800-volt system that allows great fast charging rates without compromises.
Did I forget anything? What do you expect from next generation electric cars? How can today’s electric cars become even better?