Electric Vehicle A-Z

Li-ion batteries consist of four parts: Anode, Cathode, Electrolyte & Separator. The Anode, made out of Lithium-Carbon (Graphite), is the negatively charged electrode.

When charging, lithium ions flow through the electrolyte from the Cathode and store in the graphite. When discharging, they flow back to the Cathode. Electrons, separated from the Lithium ions, move along the conducting wire connecting the Cathode to the Anode, generating electricity.

Whilst Graphite works very well at storing Lithium ions; its structure increases the volume & weight of the battery without contributing to the energy density. The next generation of batteries, to support millions of EVs on the road, will require improvements in the battery’s energy density; the capacity of the Anode is currently a limiting factor.

Silicon is a promising (and cheaper) solution, which some manufacturers are already adding to the graphite, enabling the Anode to absorb more Lithium. A Silicon-based Anode would increase the capacity; however, lithium absorption causes the Silicon to expand, change shape, and break down very quickly during repeated charging.

Whilst Battery is the generic term, the battery system in electric vehicles consists of three elements: battery cells, battery modules and the battery pack.

A battery cell is the individual Li-ion battery as described in “A is for Anode”. A battery cell can be either a cylindrical, prismatic or pouch battery, each with its advantages and disadvantages and different EV manufacturers favour the different formats.

Grouping Battery Cells together in a frame or stack creates a Battery Module; this format makes production, installation and maintenance simpler and protects the cells from external shocks, heat and vibration.

The Battery Pack is then a series of Modules together with a Battery Management System (BMS) and (typically) a liquid cooling system. The modular system enables the same car to have different battery capacities in the same battery pack. The VW ID.3 has 24 cells in each module and 7, 9 or 12 modules for the 48, 62 and 82 kWh variants.

The positive electrode. A Li-ion battery is a catchall title for different Cathode compositions, each with pros and cons. However, this is what largely determines the battery performance.  Lithium Cobalt Oxide (LCO) is the most common form in consumer electronics due to the high energy density of Cobalt. Still, its life span, thermal stability and loading capabilities make it unsuitable for EVs.

As well as Cobalt being difficult and very expensive to obtain, EV manufacturers also face severe challenges in the ethical sourcing of Cobalt. A significant proportion of the global supply comes from the DRC, where some mines are prevalent in unsafe working conditions and underage labour.

The Cathode accounts for around 25% of the cell cost. Hence manufacturers pushing to reduce the Cobalt content. Nickel, which has a higher energy density and is cheaper and easier to obtain, is increasingly replacing Cobalt in different combinations.

DC vs AC. Electricity to power an EV comes in two forms: Direct Current (DC) and Alternating Current (AC), both are essential, and one is not better than the other.

Electrical generators (except Solar) naturally generate AC. It is easier to transmit AC through hundreds of miles of pylons and wires. The mains electricity supply to our homes and what comes out of our plug sockets is AC (230V). However, most electrical devices, such as televisions and fridges, prefer DC power because of its smooth constant flow and voltage.

When it comes to devices with batteries, such as phones, laptops and EVs, these can only store power as DC. Therefore the power also needs converting into DC before it can charge the battery. Most (if not all) electrical devices in your home have a converter (often in the plug) that converts the power from AC to DC. From an EV perspective, the difference (and subsequent implications in terms of charging speeds) is essentially about where the power is converted – inside or outside the car.

The EPCU does what it says on the tin and controls the electrical systems in an EV. It integrates most devices that control the flow of electric power and consists of the inverter, the Low Voltage DC-DC Converter (LDC) and the Vehicle Control Unit (VCU).

The inverter converts the DC power supply stored in the battery into AC; inverting the current flow to the motor controls the motor speed. In other words, the inverter is responsible for controlling the acceleration and deceleration of the motor and, therefore, the EV.

Like any other car, an EV has a standard 12V battery to power all the electrics such as the lights, entertainment system, heating and cooling, etc. These systems all use electricity in low voltage. So the LDC converts the high voltage electricity in the main battery into low voltage to charge the 12V battery and power these systems.

The VCU is, perhaps, the most crucial element within the EPCU. It manages all the power control systems in an EV, including motor control, regenerative braking, AC load management, and the electronic systems’ power supply.

Electricity generated onboard the vehicle powers the FCEVs via hydrogen gas passing through a fuel cell stack. The powertrain of an FCEV is similar to that of an EV. Electricity (as DC) from the fuel cell either goes to power the inverter to create AC to drive the vehicle’s electric motor or to the inverter to charge it.

A fuel vehicle consists of many individual cells, and in each cell, a chemical reaction takes place between hydrogen molecules (H2) and the oxygen (O2) present in the ambient air.

Most FCEVs use proton exchange membrane (PEM) fuel cells: hydrogen is supplied (from onboard high-pressure storage tanks) to a negative electrode (Anode), when on-boards activated on a catalyst, causing electrons to be released. These electrons move from the negative to the positive electrode, generating electricity.

At the cathode, the protons, oxygen from the air and free electrons react to form water as a by-product of the process.

There are two different UK Government grant schemes to help drivers and organisations adopt EVs.

You can find more information on all schemes at: https://www.gov.uk/plug-in-car-van-grants

There is a constant incorrect perception around EVs, repeated by the media and the automotive industry, around annual mileage. The message is that EVs are best suited to short journeys, which translates into EVs being only suitable for people with low annual mileage. This perceived annual mileage threshold at which an EV becomes unsuitable varies, but it is usually 10k, 15k or maybe 20k.

However, driving 110 miles a day for work, five days a week for 46 weeks of the year = 25,000 miles. If you then factor in additional weekend private mileage, this could easily be 30,000 miles a year. According to the EV Database, the real-life average range of EVs on the market today is approximately 190 miles, so more than capable of achieving 110 miles a day.

However, if we use 190 miles a day in our example, this equates to 43,700 miles a year, plus when you include the extra private mileage, we’re getting close to 50,000+ miles a year. Of course, this ignores that you can always charge up for extra range on longer journeys.

In short, EVs are not just for low annual mileage drivers and so don’t listen to anyone who tries to tell you otherwise! To learn more about switching to EV, please see our electric vehicle consultancy page.

Public infrastructure is no stranger to negative media. Some of it is justified (the reliability of specific networks), but much of it is unnecessary scaremongering. “Not enough charge points” is the main message we hear from the press and the public (even though they have no idea how or where you would charge an EV!).

However, the issue of charge points is far more complex than just quantity. Having suitable chargers in the right locations is more important than just a pure numbers game. Is the charging network adequate for the average person to feel confident in moving to an EV today? Pretty much (mainly if you can charge at home).

Is it adequate for everyone to move to an EV today? Of course not, but 100% EV ownership is not far away. However, when you consider the improvement in the last 10 – 20 years, who knows what will be possible?

Are there some serious gaps in certain parts of the country/road networks? Of course, but this is being rapidly addressed and doesn’t present an issue for most people. Network growth is vast. There are nearly twice as many rapid chargers and almost four times as many ultra-rapid as two years ago. That’s an average of 700 per month (despite Covid).

If you are going on a journey beyond the range of your car, then you will need to do some light planning to ensure that you have no charging problems on route. Understanding the realistic real-life range is essential; this will be impacted by how much the car is loaded, the weather and the driving type (i.e. long motorway stretches vs rural or urban routes).

For anyone getting a new EV, perhaps the best source of real-life information is the EV-Database. My favourite journey planner App is WattsUp! Whereas Zap-Map is an invaluable source of network information, but there are many others.

Plan your charging stop to be well under the range of the car in case of problems. For example, if the range shows 200 miles, then aim to charge perhaps around 150 miles. If there is a problem at your chosen stop, you have plenty of range to get to the next one. You should be stopping approximately every 2 hours anyway (100 miles) so use this time to charge. If possible, plan to stop at a location with more than one charge unit to reduce the chance of a queue or a broken unit.

Kilowatt-hours (kWh) is the unit of energy often associated with electric vehicles.  Essentially, a kWh is the amount of energy required to run a 1000-Watt appliance running for an hour.

Often, EV manufacturers will specify how many miles their vehicle can travel per kWh. The larger the number, the more energy-efficient the vehicle is.

According to Auto Express, the electric vehicle which has the longest range in 2021 is the Mercedes EQS. This EV can supposedly travel 485 miles on a single charge!

Of course, this represents the top end specification for Electric Vehicles. However, this range shows how the technology continually improves, which should help overcome ‘range anxiety’.

EVs don’t have an internal combustion engine (ICE), but they have an electric motor that takes power from the battery (converted from DC into AC by the inverter) to drive the wheels. Motors are smaller and quieter with less inverters than engines. Thus creating additional space within the car and making for a smoother and more pleasant driving experience.

An electric motor’s torque is what sets it apart from the ICE; an EV can achieve ‘peak or maximum torque’ instantly, giving you immediate and consistent acceleration, whereas an ICE takes time to reach peak torque. This is why EVs are ‘Torque of the town…’! This immediate acceleration makes EVs fun to drive but also is very helpful when wanting to overtake.

Motors also act as a generator to convert the kinetic energy lost when the car decelerates back into stored energy in the battery pack – otherwise known as braking regeneration.

Energy conversion (stored to kinetic and back again) is not 100% efficient, so some energy is always lost during this process. However, braking regeneration does improve the overall fuel efficiency of the vehicle.

EVs don’t have an internal combustion engine (ICE), but they have an electric motor that takes power from the battery (converted from DC into AC by the inverter) to drive the wheels. Motors are smaller and quieter with less inverters than engines. Thus creating additional space within the car and making for a smoother and more pleasant driving experience.

An electric motor’s torque is what sets it apart from the ICE; an EV can achieve ‘peak or maximum torque’ instantly, giving you immediate and consistent acceleration, whereas an ICE takes time to reach peak torque. This is why EVs are ‘Torque of the town…’! This immediate acceleration makes EVs fun to drive but also is very helpful when wanting to overtake.

Motors also act as a generator to convert the kinetic energy lost when the car decelerates back into stored energy in the battery pack – otherwise known as braking regeneration.

Energy conversion (stored to kinetic and back again) is not 100% efficient, so some energy is always lost during this process. However, braking regeneration does improve the overall fuel efficiency of the vehicle.

The myriad of charging networks is perhaps one of the most ‘daunting’ or confusing aspects of EV ownership. A quick count on the Networks filter on Zap-Map, and there are around 70 different networks listed. In reality, like everything to do with EVs, it’s not that complicated. Yes, there are many individual local networks, but you don’t need to worry about these unless you live in that area (and cannot charge at home). Charging then becomes an ‘on-the-go issue.

For longer journeys across the country, you can comfortably rely on networks like Alfa Power, BP Pulse, Genie Point, Instavolt, Osprey and Shell Recharge. Charge your car, which gives you access to multiple regional networks, is an excellent extra to know, and ChargePlace Scotland is a must if you live north of the border!

As we explored before, power comes from the grid as AC. In contrast, the battery stores power as DC. The role of the onboard charger is, therefore, to convert the AC electricity provided by on-board sockets or standard / fast chargers into DC for the battery. Essentially the difference between (slow/fast) AC charging and (rapid) DC charging is where the conversion from AC power into DC. i.e. inside or outside of the EV. This is done in the car through the onboard charger in AC charging, whereas a DC rapid charge unit has the converter built-in.

The basis of EV charging speed is the power of the charger and the capability of the on-board charger. AC Charge units are typically 7kW or maybe 11kW, but the on-board as fast as 22kW; onboard chargers are also typically 7kW or 11kW, but some are capable of on-board2kW. Why is this interesting or useful for the driver? Well, a car with a 7kW onboard charger will only take 7kW even if connected to a 22kW charge onboard

As we explored earlier, the typical cathode composition of a Li-ion battery is either NCA or NMC, which rely on Nickel and Cobalt, both of which are expensive and come with mining challenges.

Lithium Iron Phosphate (LFP) may be the next step forward in EV battery development (or it may not!)

LFP batteries are not new, and the complete lack of Nickel and Cobalt presents a real long-term environmental advantage over NCA/NMC. Also, LFP batteries are safer in terms of thermal stability, experience a slower rate of capacity loss and potentially have a longer lifecycle. However, LFP has a lower energy density and operates at a lower voltage.

LFP batteries have hit the news recently with a new development on improving charging speeds. Scientists at Penn State University have tested a thermally modulated self-heating LFP battery that enables ultra-fast charging. The near future may involve different battery solutions from EV manufacturers, with LFP used in low cost / low range models but NCA/NMC used in longer-range, more expensive models.

Electric vehicle salary sacrifice is a scheme developed that allows employees to pay for an electric car through their gross salary. The employee uses gross salary to pay for the car. Consequently, the income tax assesssment utilises the remaining salary and the BIK value. The salary sacrifice scheme includes tax, insurance, servicing and maintenance, breakdown cover and accident management.

Electric vehicle salary sacrifice is a key aspect of the work EVP Solutions undertake. If you would like assistance in implementing a salary sacrifice scheme, please contact us.

Total Cost of Ownership (TCO) is the purchase price of an asset plus the cost of operating the vehicle. Although EVs are relatively expensive when initially purchased, they are far cheaper to run and maintain. Namely due to the cost of recharging the vehicle, the lack of tax and reduced maintenance costs.

The TCO should always be taken into consideration when purchasing new vehicles. Assisting in calculating TCO is an underpinning part of the EVP remit.

The uptake of both fully electric vehicles and hybrids has increased exponentially over the past couple of years. Particularly following the government announcement that the sale of diesel and petrol cars will cease from 2030, moving forwards from the original 2040 date. According to the RAC, 238,830 solely battery-powered vehicles were on the roads in 2021, compared to only 98,846 in 2019. Plug-in hybrids have also increased by almost 100,000 in the same period.

There is also a possibility these dates could change following the publication of this Electric Vehicles A-Z, so keep your ears open!

All-electric vehicles are exempt from vehicle tax as long as the electricity comes from an external source, The tax exemption is in place to encourage people to purchase vehicles that put less strain on the environment.

Considering vehicle tax when calculating the TCO is crucial, and is seen as one of the key benefits of purchasing EVs.

All-electric vehicles are exempt from vehicle tax as long as the electricity comes from an external source, The tax exemption is in place to encourage people to purchase vehicles that put less strain on the environment.

Considering vehicle tax when calculating the TCO is crucial, and is seen as one of the key benefits of purchasing EVs.

Wireless charging is a key area for development in the EV world if they become as practical as traditional petrol and diesel engines. The government has announced plans to invest £40 million specifically into wireless charging.

In 2020, a new trial was launched in Nottingham, which saw electric taxis utilising wireless charging to test their suitability for the wider population.