This course compares the driving principles of petrol and diesel cars and electric vehicles, and explains the advantages of electric vehicles in terms of environmental pollution and maintenance costs. It also covers the types of electric vehicles and the potential for advances in battery technology, and discusses the challenges and future prospects for commercialising electric vehicles.

Comparing petrol and diesel cars to electric vehicles

Recently, an unusual thing happened: the stock price of an American car company skyrocketed by more than 1000%. Tesla is an electric car company founded by Elon Musk, the founder of PayPal, along with four fellow engineers. Musk is leading a new wave in the automotive market by making battery-powered cars a reality, something that was only possible in his imagination. The demand for electric vehicles is growing rapidly, not only because of the growing global concern for environmental pollution, but also because they are very low-cost to maintain for consumers. As a testament to this, it is estimated that electric vehicles will account for around 20 per cent of the total car market by 2025. It’s safe to say that electric vehicles have become an essential choice for car companies.
In fact, the need for electric vehicles has been around for a long time. As global warming and environmental problems caused by automobile emissions became more prominent, the need for electric vehicles emerged as a solution, but battery power and charging times made it difficult to commercialise them. However, recent advances in electronics technology, including smartphones, have improved battery efficiency, making it possible to mass-produce electric vehicle models. In this article, we’ll take a look at how electric vehicles work, compare them to conventional petrol and diesel cars, and discuss the future of battery technology.

How petrol and diesel cars work

Most rear-wheel drive cars follow the basic structure established in 1891 by the Frenchman Panard Lebasso. A car is made up of around 30,000 parts, divided into two main parts: the body and the chassis. The chassis is the part that generates the power needed to drive the car, which in turn is divided into the engine, transmission, and wheels. In a petrol car, high-pressure, high-temperature gases produced by the combustion of fuel and oxygen in a cylinder expand to move a piston. This is a four-stroke cycle of intake, compression, power, and exhaust, and the exhaust emissions released into the atmosphere during the exhaust stroke are a major source of environmental pollution.
Diesel cars are powered in a similar way to petrol cars, but the fuel is ignited in a different way. Diesel engines are more fuel efficient and have more torque than petrol engines, but they have emissions and noise issues. By burning fuel at higher pressures, diesel engines are more thermally efficient, but technical improvements are needed to address emissions, including particulate matter and nitrogen oxides.

How electric vehicles work

Electric vehicles, on the other hand, are powered by electricity, which is used as a power source to turn a motor. Unlike petrol and diesel cars, they are structurally simple because they do not require a piston engine, and they are characterised by virtually no engine noise. Electric vehicles are divided into different types depending on the power source they use. The first is the hydrogen fuel cell vehicle (FCEV). These cars use hydrogen as a fuel to generate electricity in a fuel cell. In a fuel cell, hydrogen and oxygen undergo a chemical reaction to generate electricity, and the only emissions are water. However, the infrastructure such as hydrogen refuelling stations is not yet in place, so commercialisation will take time.
The second is battery electric vehicles (BEVs). These cars charge electricity into a battery built into the vehicle and then use that electricity to drive a motor. They are sometimes called ‘pure electric vehicles’ because they are powered by pure electricity. These are the models that Tesla produces. However, battery electric cars take longer to charge and have limited battery performance. There are also issues with the use of fossil fuels in the production of the batteries, which challenges their reputation as a green technology.
The third is the hybrid electric vehicle (HEV), which uses a small internal combustion engine to compensate for the limited storage capacity of the battery. The internal combustion engine can be used to charge the battery while driving, making it a transitional technology between battery electric vehicles and conventional petrol vehicles.

The evolution and future of battery technology

Battery technology is one of the most important factors for the popularisation of electric vehicles. Currently, most electric vehicles use lithium-ion batteries, which are relatively efficient but have a low energy density, meaning that the range of a single charge is shorter than that of internal combustion engine vehicles. To address these issues, next-generation battery technologies such as solid-state batteries are being researched around the world. Solid-state batteries use solids instead of liquids as the electrolyte, which has the potential to increase safety, energy density, and reduce charging times. If these technologies are commercialised, it is expected that the range problem of electric vehicles will be largely solved.
Battery recycling technology is also emerging as an important issue. It is necessary to develop technologies that can effectively recycle lithium-ion batteries at the end of their life cycle. If battery recycling technology is successfully introduced, the environmental benefits of electric vehicles will be further extended.

Challenges to commercialising electric vehicles

The challenges to commercialising electric vehicles are not only technical advances, but also a combination of infrastructure and policy support. In recent years, countries have announced a range of regulations and support to promote the commercialisation of EVs.
In the US, the Inflation Reduction Act (IRA) of 2022 has been passed, benefiting manufacturers of electric vehicles, and new policies related to tighter CO₂ emissions standards are also in place. The European Union (EU) also published the EU Battery Regulation in 2023, strengthening legislation to promote sustainable battery management and recycling. The regulation aims to minimise the environmental impact of batteries over their entire lifecycle and encourage a circular economy.
The biggest challenges to the commercialisation of electric vehicles are charging infrastructure and battery performance. Countries are investing huge amounts of money to expand charging infrastructure, with Europe and the US implementing policies during 2022-2023 that focus on installing charging infrastructure. In response, battery technology is also advancing rapidly. The demand for lithium-ion batteries continues to grow, and by 2023, battery performance and productivity will have improved significantly.
In addition, new battery technologies – solid-state batteries and lithium iron phosphate (LFP) batteries – are reducing battery costs, extending their lifespan, and making electric vehicles more competitive. In particular, these batteries are expected to play an important role in a sustainable future electric vehicle industry by reducing the use of rare metals.
Therefore, challenges such as expanding charging infrastructure, improving battery performance, and enhancing battery recycling technologies still remain for the commercialisation of electric vehicles, but policy support and technological innovation around the world are rapidly addressing these issues.