Solid-state batteries have long been believed to bring about substantial changes in the electric vehicle (EV) industry. Compared to today’s lithium-ion batteries, solid-state batteries offer higher energy density, which can potentially double the range of electric vehicles and enhance charging speeds and safety.
In spite of these significant engineering challenges, recent advancements in solid-state battery technology have brought us closer to commercialization. There are several reasons to be optimistic about the future of solid-state batteries, based on the latest developments in the field.
Let’s get some insight about them.
Exactly What Are Solid-State Batteries?
Solid-state batteries in electric vehicles are different from the lithium-ion ones. Unlike lithium-ion batteries, which use liquid electrolytes between electrodes, solid-state batteries make EVs lighter, more efficient, and give them a longer range because of their higher energy density.
There are also some great advantages to solid-state batteries. They are safer and charge more quickly than the batteries we currently use. Their stability is also maintained even when they are being charged or when it is very hot. Many experts believe that solid-state batteries are the future of battery technology and will be a big deal soon.
One of the biggest problems with solid-state batteries today is the formation of dendrites. When these batteries are charged, tiny lithium particles can accumulate on one side, causing a bump. Eventually, these bumps can grow into dendrites, which are branch-like structures. During the formation of dendrites, the battery’s protective coating can be damaged and become uneven. This can be dangerous. If these structures break through the battery’s insides, they could even cause a short circuit and start a fire.
Solid-State Batteries: Latest Research
Harvard School of Engineering and Applied Sciences (SEAS) researchers have created a new kind of battery that can be charged and discharged 6,000 times. This is the highest capacity of any pouch battery available.
In the past, there was a recurring issue with a battery component called the anode developing dendrites on its surface. Back in 2021, researchers suggested a new battery design with multiple layers that used different materials to control the growth of these dendrites instead of trying to stop them from forming.
Moreover, recent research has led to the development of an anode featuring micron-sized silicon particles that prevent dendrite formation. This innovative technique allows for a thick, uniform layer of lithium metal to be plated around the silicon core, which results in a smooth surface that ensures even current density distribution and prevents dendrite growth.
With this improved design, the researchers claim that the battery can be recharged within ten minutes.
In What Areas Does Toyota Work?
According to academic standards, there is limited information available regarding this “technological breakthrough that resolves the long-standing problem of battery durability.” A new partnership with Idemitsu Kosan, the second largest oil refiner in Japan, provided us with a few insights into the company’s future plans in November. The primary business of Idemitsu consists of extracting crude oil and converting it into commercial chemicals, such as plastics and lubricants.
By using by-products from Toyota vehicles, Toyota has been developing battery-related materials since 2001. As part of the most recent agreement, Toyota and another company have begun collaboration on materials development. This agreement is aimed at mass producing and commercializing solid-state batteries utilizing sulfuric acid electrolytes.
Toyota has announced that their solid-state batteries are projected to achieve a range of over 1,200 kms and can be charged from 10% to 80% in 10 minutes or less. In comparison, Tesla’s Model Y offers a range of 542 kilometers and can be fast-charged in 27 minutes, while the Model S has a range of 620 kilometers.
Each company is building a larger facility to integrate materials manufacturing and battery assembly. Idemitsu has a small-scale electrolyte production facility, and both are building a larger facility. As per their roadmap, commercial batteries should be ready by 2027-28, followed by mass production. Even though it’s hard to tell whether this timeline is feasible, the company is making progress.
The electrodes and the electrolyte have a hard time staying in contact in solid-state batteries. Additionally, repeat charging and discharging can lead to cracks between these components, which ultimately reduces the battery’s lifetime. It’s Toyota’s CEO, Koji Sato, who said that the key to resolving these issues is to develop highly flexible, adhesive, and crack-resistant solid electrolytes. Both companies hope to create solid-state batteries with high performance and extended durability by combining their expertise.
At the moment, there are not many details about this topic. Due to potential commercial implications, it seems like patents are being filed instead of peer-reviewed papers. A JustAuto article said Toyota has filed 8,274 patents on solid-state batteries, with an example dating back to 2016. It seems like an effort has been made to protect intellectual property.
Does Anyone Else Work on Solid-State Batteries?
Several automakers, including Hyundai, Kia, and Honda, are currently conducting research on their own solid-state batteries. However, they are trailing behind Toyota-Idemitsu in terms of the number of patents.
Apart from this, companies like Volkswagen, Ford, BMW, and Mercedes-Benz have collaborated with external battery manufacturers to explore solid-state battery development. Nissan and Honda have also made commitments to advancing solid-state battery technology. At present, Tesla has not disclosed any information regarding solid-state batteries.
The Challenges of Implementing All-Solid-State Batteries
Solid-state batteries offer various benefits, but their practical implementation poses several challenges. At present, the technology is still in its early stages, with key hurdles including manufacturing processes, material identification, and the development of efficient conducting materials.
●Economical and scalable manufacturing
Scalable manufacturing has many engineering challenges. For example, some cells need external pressures over 100 MPa to be assembled. Also, some studies used cathodes with lower active loads than liquid electrolytes. However, more research is needed to better understand the morphology of anodes and cathodes, as well as how they affect energy density.
●Conductivity of solid-state electrolytes
Measuring the ionic conductivity of a solid-state electrolyte requires precise and accurate techniques. Currently, conductivity is typically measured as bulk resistance, which can vary based on factors such as the type of electrolyte material, frequency, and temperature.
●Optimizing electrode materials
In all-solid-state batteries, the solid-state electrolyte plays a crucial role and can be made of ceramic, glass, polymer, or a combination of these materials. The choice of material further influences the electrical, electrochemical, and mechanical properties of the battery.
However, selecting the most suitable material is challenging due to the varying reactions of different materials at different temperatures. Apart from this, integrating these materials with electrodes remains a challenge, and the use of carbonaceous materials may be necessary. Although all-solid-state batteries may have difficulties, many companies are researching their potential.
●All-solid-state battery advancements
The widespread adoption of all-solid-state batteries faces several challenges, and researchers and companies are actively developing innovative solutions to overcome these challenges in response to these challenges. By engaging in collaborative efforts, supporting government policies, and achieving safety certifications, it is possible to achieve a global promotion of energy storage.
In a solid-state battery, the electrolyte can be ceramic, glass, polymer, or a combination of those. Remember that the material chosen determines how the battery works electrically, electrochemically, and mechanically. Due to the different reactions of various materials at different temperatures, choosing the right material can be challenging. The integration of these materials with electrodes may also require carbonaceous materials.
A Roadmap for Advancing All-Solid-State Batteries
Both companies and researchers are working on innovative solutions to overcome the challenges faced by all-solid-state batteries. Moreover, forming partnerships, implementing supportive government policies, and getting safety certifications are key to achieving cleaner energy storage.
The following solutions will contribute to the advancement of all-solid-state batteries:
●Efforts in collaborative research
Lately, there have been some significant collaborations between universities, research institutions, and companies. Here are a few examples:
- Tsuyo Manufacturing and IIT Delhi are working together to make the manufacturing process more efficient and reduce the cost of electric vehicles.
- IOCL and Phinergy, an Israeli company, are teaming up to create lightweight versions of metal-air batteries.
- MIT has developed a way to make electrode interfaces more stable, which is helping Toyota in making advanced solid-state batteries.
- A study at Stanford, sponsored by Samsung, suggests that using ceramic in solid-state batteries should be done cautiously.
- Volkswagen and Northvolt acquired a company called Cuberg to work towards achieving higher energy density in batteries by 2025.
These partnerships are pushing forward the technology of solid-state batteries by combining knowledge and insights.
●Techniques for improving manufacturing
New manufacturing methods are being developed to make better batteries. These methods can help make batteries that last longer and hold more energy.
- One way to do this is by using thin layers of a special material to control how the battery works.
- Another way is by building batteries on conveyor belts, which can make them faster and cheaper.
- Also, using a certain type of material called graphite for part of the battery can make it work even better.
These new methods could help make better batteries for lots of different things.
● Policy Initiatives and Government Support
To advance the development and commercialization of solid-state batteries, it is crucial for governments to initiate supportive policies and increase research funding.
Some key policy initiatives include increasing government research grants to foster innovation in battery technology, offering tax incentives to companies that produce all-solid-state batteries to promote widespread adoption, broadening the use of such batteries through supportive regulations for electric vehicles, and establishing a favorable regulatory environment coupled with financial incentives to expedite the shift to sustainable transportation.
●Requirements for safety and certification
Battery technology continues to advance, with all-solid-state materials showing promise for improved efficiency and safety compared to traditional lithium-ion batteries. However, ensuring safety certifications for electric vehicle (EV) owners is crucial.
Implementing these certification requirements may pose challenges:
- Solid-state batteries have unique characteristics based on the electrolyte material, which may complicate the certification process.
- It may be more practical to conduct comprehensive testing across various operating conditions to guarantee the safety of these batteries.
- Establishing consistent safety standards across different regions is challenging, akin to defining universal traffic rules.
Despite these challenges, international organizations and governments are working towards creating safety standards and certifications.
●Taking safety measures
The latest advanced battery systems require robust safety measures to ensure their protection, including:
- Fire-resistant casings for solid-state batteries that can withstand thermal events.
- Implementation of a sophisticated thermal management system for all batteries to maintain safe operating temperatures.
- Continuous monitoring of battery performance and automatic shutdown in case of irregularities by a battery management system (BMS).
Implementing these measures is an important initial step in making battery manufacturing safer.
●The certification standards
When it comes to new kinds of batteries for electric cars, safety is really important. There are some rules and standards that these batteries have to meet to make sure they are safe and reliable.
For example, lithium batteries have to pass tests for safety and performance according to a rule called UN 38.3.
There are also other standards that define how well lithium-ion batteries should work and how safe they need to be. One of these is called IEC 62660-1.
Another standard, UL 2590, says that electric vehicle batteries need to meet specific safety and performance rules, like being able to handle high temperatures and staying safe even if there’s an accident.
These rules are important for all-solid-state batteries too, because they show how safe and well the batteries work.
An All-Solid-State Battery for Electric Mobility
Electric mobility is set to undergo a significant transformation with the widespread adoption of all-solid-state batteries. EVs are appealing to consumers due to their higher energy density, which enables them to achieve longer driving ranges and speedier charging times. This advancement will not only improve the performance of vehicles but will also contribute to the reduction of greenhouse gas emissions, paving the way for a greener, more sustainable future for transportation.
To fully realize their potential, all-solid-state batteries must continue to advance. Through improved access and technology improvements, these batteries will play a significant role in influencing the electric vehicle market (EV), promoting sustainability initiatives, and accelerating the global switch to cleaner energy sources. In the coming years, all-solid-state batteries will be able to propel electric mobility towards a greener and more efficient future.
