As the electric vehicle (EV) industry charges ahead, the demand for more efficient, faster, and reliable charging systems has become a significant challenge. For EV adoption to continue at its current pace, addressing the limitations of existing charging infrastructure is critical. Traditional silicon-based semiconductors, which have been the backbone of the electronics industry for decades, are now reaching their physical limits in terms of power efficiency, switching speed, and heat tolerance. Wide-bandgap (WBG) semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN), have emerged as a timely solution to these problems, offering transformative potential for EV charging applications.
This article looks at how WBG semiconductors are revolutionising EV charging systems, offering unique advantages over traditional silicon devices and potentially unlocking a more efficient, sustainable future for EV technology.
Fundamentals of WBG Semiconductors
Before diving into their applications, it’s essential to understand what makes WBG semiconductors unique. A semiconductor’s band gap is the energy difference between its valence band (where electrons are bound) and its conduction band (where electrons are free to move and conduct electricity). The size of this band gap determines many of the material’s electrical properties, including how well it can handle heat, voltage, and switching speeds.
Traditional silicon semiconductors have a relatively narrow bandgap, typically around 1.1 electron volts (eV). This makes them suitable for many standard electronic applications but less ideal for high-power, high-temperature environments like EV charging. WBG materials, by contrast, have a much larger bandgap — SiC’s is around 3.3 eV, and GaN’s is approximately 3.4 eV. This wider bandgap enables WBG devices to operate at much higher voltages, temperatures, and switching frequencies than their silicon counterparts, opening up new possibilities for power electronics.
Advantages of WBG Semiconductors in EV Charging
See how Avnet Silica is supporting the latest innovative EV solutions. From the forecourt to the cloud, we complement your skillset to get your EV charging requirements deployed faster, better and stronger.
SEE EV OVERVIEWThe unique properties of WBG semiconductors bring several critical advantages to EV charging systems, particularly in terms of efficiency, speed, and reliability.
1. Higher Voltage and Power Handling Capabilities
One of the most significant benefits of WBG semiconductors is their ability to handle higher voltages. SiC and GaN devices outperform traditional silicon by a wide margin in fast-charging stations, where rapid energy transfer is necessary. These materials can withstand higher electric fields, which allows them to manage higher voltages without breaking down. This is particularly important for high-power charging stations, where the ability to handle larger voltages means faster charging times for EV owners.
In addition, WBG devices can reduce energy losses during power conversion. Power loss in semiconductor devices often occurs due to resistance during switching operations. Because WBG materials allow for faster and more efficient switching, they minimise these losses, making the overall charging process more efficient.
2. High-Temperature Operation
EV chargers generate significant amounts of heat, particularly those designed for fast charging. Traditional silicon-based power electronics need extensive cooling systems to prevent overheating, which adds both complexity and cost to the overall system. WBG semiconductors, however, can operate at much higher temperatures — upwards of 300°C for some SiC devices — without compromising performance.
This high-temperature tolerance has two key benefits for EV charging systems:
- Improved reliability: WBG devices are less prone to overheating, which enhances their reliability over long periods of operation. This is crucial in EV charging stations, which must endure continuous use without frequent maintenance.
- Reduced cooling requirements: Since WBG devices generate less heat and can tolerate higher temperatures, they require less cooling infrastructure, reducing the system's size, weight, and cost.
3. Faster Switching Speeds and Higher Efficiency
Switching speed is another area where WBG semiconductors excel. The faster a semiconductor can switch between conducting and non-conducting states, the more efficiently it can manage power flow. WBG devices, particularly GaN-based ones, can switch at much higher frequencies than silicon-based components, enabling more precise power delivery control in EV chargers.
Faster switching speeds result in reduced energy losses during the charging process. This translates to higher energy efficiency, reducing the environmental impact of EV charging and lowering operating costs for charging station operators. As charging systems become more efficient, the overall energy demand from the grid decreases, helping to balance the energy load as EV adoption continues to grow.
Applications of WBG in EV Charging Infrastructure
WBG semiconductors are already being integrated into various parts of the EV charging ecosystem, from charging stations to onboard chargers (OBCs) within the vehicles themselves. Their ability to improve power density, efficiency, and thermal management makes them ideal for high-power public chargers and the compact, efficient systems needed inside EVs.
1. Fast Charging Stations
The rise of fast charging stations, which can charge EVs in a fraction of the time compared to standard chargers, has been crucial for expanding EV adoption. However, traditional silicon-based power electronics need help to handle the high power levels required for fast charging, leading to inefficiencies and excessive heat generation.
WBG semiconductors, particularly SiC, are now being used in fast chargers to address these challenges. SiC devices can manage higher voltages and power levels, enabling speedier charging times while maintaining energy efficiency. By reducing energy losses and the need for complex cooling systems, SiC-based chargers are faster and more cost-effective over the long term.
2. On-Board Chargers (OBCs)
While charging infrastructure is essential, the vehicle's on-board charger (OBC) is equally important. OBCs convert the alternating current (AC) from charging stations into direct current (DC) to charge the EV’s battery. This conversion process is another area where efficiency is critical, as energy losses during charging can directly impact vehicle range and battery life.
GaN-based semiconductors are increasingly being used in OBCs due to their ability to improve power density and efficiency. GaN devices can handle higher frequencies, which allows for smaller, lighter OBC designs. This is a significant advantage in EVs, where reducing weight and size is crucial for optimising vehicle range and performance.
Future Outlook: WBG Semiconductors in the EV Ecosystem
As EV adoption grows, the need for more efficient, scalable charging infrastructure will only increase. WBG semiconductors are well-positioned to play a central role in this future, offering a path toward faster, safer, and more reliable charging solutions.
1. Vehicle-to-Grid (V2G) Integration
Looking further ahead, WBG semiconductors could facilitate the integration of vehicle-to-grid (V2G) technologies, where EVs act as energy consumers and providers. In a V2G system, EVs could feed excess energy back into the grid during peak demand periods, helping to stabilise the grid and reduce reliance on traditional power plants.
For V2G to become a practical solution, the power electronics involved must be highly efficient and capable of handling bidirectional energy flow. WBG semiconductors, with their high efficiency and fast switching capabilities, are well-suited for this role, enabling seamless energy transfer between vehicles and the grid.
2. Sustainable Energy and Smart Grid Applications
WBG semiconductors could also contribute to the broader integration of renewable energy sources into the grid. As solar and wind power become more prevalent, managing the variability of these energy sources will require more advanced power electronics. WBG devices, with their ability to handle high voltages and rapid switching, are ideal for managing complex power flows in a smart grid powered by renewable energy.
A Timely Solution for a Critical Need
The rapid growth of the EV market has created an urgent need for more efficient, faster, and scalable charging solutions. Traditional silicon-based semiconductors can no longer meet these demands, but wide-bandgap semiconductors, particularly SiC and GaN, offer a timely and compelling solution.
With their ability to handle higher voltages, operate at elevated temperatures, and switch at faster speeds, WBG semiconductors are reshaping the EV charging landscape. From fast charging stations to on-board chargers, WBG technology is enabling faster, more reliable, and energy-efficient charging solutions, paving the way for the future of electric mobility.
As the technology continues to evolve, WBG semiconductors will improve EV owners' charging experience and contribute to developing a more integrated, sustainable energy infrastructure. Whether through faster charging, vehicle-to-grid integration, or renewable energy management, WBG is proving to be the right technology at just the right time.
More from this series:
Working on an EV charging project?
Our experts bring insights that extend beyond the datasheet, availability and price. The combined experience contained within our network covers thousands of projects across different customers, markets, regions and technologies. We will pull together the right team from our collective expertise to focus on your application, providing valuable ideas and recommendations to improve your product and accelerate its journey from the initial concept out into the world.
