Electric vehicles (EVs) have been gaining a lot of traction in the past few years, driven by the global shift towards clean energy and sustainable transportation.
Since they produce zero tailpipe emissions, EVs are significantly better for the environment than their petrol and diesel counterparts. This makes EVs a key technology for decarbonizing road transport, which is responsible for about one-sixth of global emissions.
They also have lower running and maintenance costs than internal combustion vehicles, making them far more efficient and affordable.
With that, the popularity and adoption of EVs are growing significantly, with nearly one in five cars sold in 2023 being electric. After crossing the 10 million mark in 2020, the number of electric cars on the road reached 40 million last year.
In 2023 alone, electric car sales were almost 14 million, 95% of which were in China, Europe, and the US. As a result of this expansion, EVs now account for about 20% of all new car sales worldwide, which is expected to surge towards 50% by 2030.
There isn’t just one type of EV, though; rather, there are several kinds:
- Battery Electric Vehicles (BEVs)
- Plug-In Hybrid Electric Vehicles (PHEVs)
- Hybrid Electric Vehicles (HEVs)
- Fuel Cell Electric Vehicles (FCEVs)
Among these, battery-powered EVs are the most common, accounting for 70% of the electric car stock in 2023.
BEVs are fully powered by electricity and can be recharged from external sources. They are more efficient than hybrid and plug-in hybrid vehicles.
Given that batteries are the energy source of EVs, they are the most important component of an electric vehicle. By replacing internal combustion engines, battery EVs can significantly reduce pollution, help integrate renewable sources like wind and solar, and ensure sustainability.
When it comes to EVs, the condition of batteries determines their performance. And it’s their size, which is measured in kilowatt-hours, that indicates just how much electricity the battery can store and how far the electric car can go on a single charge.
The higher the energy density in the battery, the greater the range per charge. Also, fast charging is essential to allowing EV owners to recharge their vehicles quickly.
Now, EVs use a variety of batteries, including lithium-ion, which is the most common. Lead acids are a popular choice, particularly in the US, for their cost-effectiveness and long service life, while lithium sulfur increases theoretical charging capacity.
Besides the growing environmental awareness and government incentives, advances in battery technology, in particular, which have made EVs more efficient and affordable, are driving electric vehicle adoption.
So, batteries play a critical role in EVs and the broader clean energy transition, which makes it essential to have a better idea of just how well they are doing and the condition they are in. For this, researchers have developed a new technology that monitors batteries’ state with high precision to maximize their efficiency and stability for the long term.
Technology for the Precise Diagnosis of EV Batteries
Researchers from the Korea Advanced Institute of Science and Technology (KAIST) made this new technology for accurate diagnosis of the state of EV batteries, which is essential for their efficient management and safe use, using just small amounts of current.
This development was announced last week by KAIST, which noted that a team of researchers led by Professors Sang-Gug Lee and Kyeongha Kwon from the School of Electrical Engineering had built electrochemical impedance spectroscopy (EIS) technology.
This EIS tech can be utilized to upgrade the performance and stability of high-capacity batteries in electric vehicles.
Electrochemical impedance spectroscopy is a powerful tool that measures the impedance magnitude and changes in a battery, which allows for the evaluation of battery efficiency and loss.
Battery impedance is simply a measure of the resistance to current flow within the battery. This non-intrusive way of preventing battery failure simply identifies early signs of weakness or deterioration and examines its performance and condition.
An important tool for assessing the battery’s state of charge and health, it can also analyze chemical or physical changes, describe thermal characteristics, pinpoint what’s causing the failures, and forecast battery life.
However, conventional EIS equipment is not only expensive but also complex, which makes it hard to install, operate, and maintain.
Then there’s the matter of precision and sensitivity restrictions, which means when we apply current disturbances of several amperes to a battery, it can result in significant electrical stress. This, in turn, increases the risk of fire or battery failure, hence making it difficult to use in practice.
So, to tackle all these issues, the engineering team from KAIST created a low-current EIS system to diagnose the condition of highly efficient EV batteries as well as their health.
This new system can measure battery impedance accurately with low current disturbances, i.e., 10mA. During the measurement process, the new EIS tech minimizes thermal effects and safety issues.
Yet another benefit of this system is that it reduces the need for bulky and costly components. So one can easily integrate it into vehicles.
The new EIS system has actually demonstrated its success in determining the electrochemical properties of EV batteries under different operating conditions. This includes various temperatures and state of charge (SOC) levels.
The system’s easy integration into the battery management system (BMS) of EVs, along with its high measurement accuracy and reduced complexity and cost compared to conventional high-current EIS methods, makes it really beneficial for EVs.
According to corresponding author Professor Kyeongha Kwon, the system can also contribute to battery diagnosis and performance improvements for energy storage systems (ESS).
Other Developments in EV Battery Condition & Safety
Given the importance of batteries, researchers have been working on different ways to get a better idea of their conditions. After all, the capacity of EV batteries declines by about 10% in about 6.5 years of consistent operation. Here, overcharging and over-discharging also contribute to this decline.
Last year, a team of Michigan Engineering researchers created a formula to diagnose and monitor a battery without tearing it apart. The formula, which can also be applied to other photonic and electronic devices, works for any combination of battery materials.
One method researchers use to investigate batteries is by applying a weak alternating current, similar to what comes from a wall plug but much weaker, to probe the battery. In this process, impedance changes depending on the frequency of the alternating current or how quickly it changes direction.
A key measure is how impedance varies with frequency, obtained by sweeping the frequency from low to high. To achieve this, a relationship must be built between the battery materials and their signature. The team, however, came up with its own formula to describe the relationship. And once impedance is measured at a few frequencies, the formula can predict impedance as a function of frequency for a wide range of frequency range.
The formula, as per the team, serves as a way to showcase material impedance using only a few experimental data points. It simplifies the whole process of modeling the movement of electricity through devices that are made with various materials and doesn’t need to know the microstructure of the material in advance, either.
It can further help design better solid electrolytes, pinpoint the impedance features of other components of batteries, and build accurate battery models to deliver safer and more efficient control when charging and discharging.
At the time, the team said that they plan to use the formula to understand and then design solid-state electrolytes with mixed materials, which can provide higher capacity and better safety.
Advances in structural battery design, materials, and monitoring systems are ongoing, which have enhanced safety measures to prevent internal short circuits and thermal runaway. For this, researchers are increasingly focusing on the role of silicon-based anodes, particularly SiO particle distribution within the anode layer, to achieve higher energy density while controlling adverse effects during cycling, thereby improving safety and longevity.
When it comes to battery design and assembly, adhesives are also emerging as a critical component, offering advantages like enhanced performance by optimizing the thermal interface between battery cells and cooling systems, greater design flexibility by bonding a variety of materials, improved energy management for safety, and cost savings through streamlining manufacturing processes.
Researchers and companies are also leveraging AI for battery material discovery and manufacturing. While EV battery technology has advanced significantly in recent years, several issues still exist in terms of material, design, range, and battery management systems.
The battery management system (BMS) in an EV is about ensuring efficiency, safety, and longevity by optimizing battery performance. Traditional battery estimations regarding its health and charge to forecast future degradation haven’t been accurate, which has led to ML algorithms for BMS that analyze real-time data for precise battery state of health (SOH) and state of charge (SOC) estimations. The BMS then uses these estimates to optimize the battery performance.
The global EV battery formation and testing market is actually a fast-growing one, which was valued at $1.9 billion in 2023. This market is projected to grow at a CAGR of over 17.6% in the next eight years to reach $7.8 bln by 2032.
This growth is driven by rising EV adoption and subsequent battery production, technology advancements in battery chemistry, battery safety, and reliability requirements, and increasing focus on sustainability and reducing carbon emissions.
A couple of months ago, the US Department of Energy (DOE) also announced $43 million in funding for projects that will advance research, development, and deployment in critical battery areas. The aim of the initiative is to drive innovations in low-cost EV battery manufacturing, reduce failures, improve battery safety, and strengthen the domestic supply chain of battery materials.
This is in line with the US National Blueprint for Transportation Decarbonization, aiming to remove all emissions from the transportation sector by 2050 by advancing battery technologies to power safe and efficient zero-emission EVs.
Companies Helping Advance EV Battery Management
Now, let’s take a look at companies that are working at a cross-section of EV battery health technology, BMS systems, and EIS advancements, all of which are crucial for sustaining the EV market and optimizing battery lifespans and safety.
Elon Musk’s Tesla (TSLA -2.48%) is among the most prominent ones, and it is deeply invested in high-capacity and long-life batteries for EVs. With Tesla shares up 4.83% this year, its market cap is currently standing at $830.7 bln.
Tesla, Inc. (TSLA -2.48%)
Then there’s the $3.24 bln market cap QuantumScape Corporation (QS -8.08%), which develops solid-state lithium-metal batteries for EVs, while the $1.9 billion market cap Enovix Corporation (ENVX +9.61%) is developing advanced silicon-anode lithium-ion batteries. The $11.18 bln market cap Albemarle Corporation (ALB +4.96%) is a leading lithium producer and is involved in improving battery efficiency and safety. The shares of QS, ALB, and ALB are down 6.47%, 34.14%, and 13.14% this year, respectively.
Analog Devices (ADI -0.01%) is a $114 bln company whose shares are up 15.67% YTD. Meanwhile, it provides battery management system (BMS) solutions for EV batteries.
Now, let’s take a deeper look at another related company that has been performing well this year.
The $59.2 billion market cap automobile giant’s shares have been experiencing a nice upside this year. With just over two months left in 2024, GM price has surged 46.77% as it trades at $52.9. It has an EPS (TTM) of 9.37 and a P/E ratio (TTM) of 5.63, along with a dividend yield of 0.91%.
General Motors Company (GM +1.23%)
General Motors is involved in the designing, building, and selling of cars, trucks, and automobile parts, in addition to providing software-enabled services. It is also pioneering advances in battery technology, safety, and performance for its EV fleet through the Ultium platform.
Ultium was first unveiled in 2020, and its CEO, Mary Barra, called it:
“A multi-brand, multi-segment EV strategy with economies of scale that rival our full-size truck business with much less complexity and even more flexibility.”
During a recent meeting, Barra announced that the Ultium battery brand is now going away but stated that EV sales will improve. GM’s EV lineup includes Chevy Equinox and Blazer, GMC Hummer EV, Cadillac Lyriq, and Cadillac Celestiq.
Kurt Kelty, GM vice president of the battery cell, however, acknowledged the importance of Ultium in helping it launch the wide range of all-new EV models, noting:
“(The company’s) transition from one size fits all to new program specific batteries.”
GM is now eyeing several battery chemistries so that it can fulfill the performance demands better.
The automobile company is also planning to build a battery prototyping center in Michigan that will open in 2027, which can help bring down the time to develop batteries by as much as a year.
This week, GM reported its financials for Q3 2024, which revealed that its revenue for the quarter was $49 billion, up 10% YoY, while adjusted automotive free cash flow came in at $5.8 billion, an increase of $900 million compared to last year. During this period, GM made $1 bln worth of stock repurchases.
The company saw its retail market share in the US grow in Q3 while the operating environment in China remained challenging. Its warranty costs also increased due to inflationary pressures.
As for EVs, the company is on track to produce 200,000 EVs in North America this year. While progressing, GM’s EV business is still working on achieving profitability and expecting a $2 billion to $4 billion improvement in EV losses.
Conclusion
As clean energy transitions accelerate sharply, aided by government policies, incentives, and industrial strategies, the world has shifted to electric vehicles. The rapid growth of EVs emphasizes the essential role of batteries and, as such, calls for high efficiency and safety. Here, technologies like electrochemical impedance spectroscopy and innovative battery management systems can help refine how we monitor EV battery health and contribute to safer, more sustainable EV usage.
As more studies, companies, and governments focus on improving EV battery diagnostics, we will see longer-lasting batteries, safer designs, and efficient power storage, all of which are crucial for EVs to achieve mainstream adoption. These innovations can further help reach ambitious global climate goals, leading to a cleaner, more sustainable future.
Click here for a list of top 10 EV stocks to invest in.
