Summary
- Electric vehicles (EVs) have gained significant traction in the global automotive industry, with EV sales reaching 14% of global passenger car sales in 2022.
- Battery electric vehicles (BEVs) currently dominate the EV market, accounting for 73% of EV sales in 202
- Solid-state batteries are seen as the next breakthrough in EV battery technology.
- Solid-state batteries offer several advantages over traditional lithium-ion batteries, including higher energy density, improved safety, shorter charging times, a wider range of operating temperatures, and a longer lifespan. Despite some challenges, solid-state batteries have the potential to revolutionize the EV industry.
Electric cars have achieved a stable foothold in the global automotive industry. In 2020, electric vehicles (EVs) made up less than 5% of global passenger car sales. In 2021, the EV segment grew to 9%, and then to 14% in 2022. Automotive manufacturers – big and small – are trying to catch up and join the EV revolution.
Although some automakers are still pursuing hydrogen fuel cell electric vehicles (HFCEVs), Battery electric vehicles (BEVs) account for the majority of EVs being sold today. Of roughly 10.5 million EVs sold globally in 2022, 73% were BEVs and almost 27% were plug-in hybrid EVs (PHEVs). Hydrogen fuel cells may still see a resurgence, but for the foreseeable future, batteries will likely be the popular choice for electrified mobility. For this reason, automotive companies are investing heavily in partnerships and in-house research and development programs to take EV battery technology to the next level.
The next great breakthrough in the BEV race is the solid-state battery – and many companies are burning the midnight oil to make it a sustainable and cost-effective replacement for today’s EV batteries.
So what is a solid-state battery? How is it different from the current EV batteries? What are the benefits of solid-state batteries? This article will answer all these questions and will give you a good idea of how solid-state batteries can change the EV industry.
What Is A Solid-State EV Battery?
A solid-state EV battery is an energy storage device that uses a solid electrolyte material to transport lithium ions between a positive (cathode) and a negative (anode) electrode. Depending on the flow of the ions, electrical energy is either stored (i.e. during battery charging) or released (i.e. during battery usage). The solid electrolyte acts as a transport medium and a physical separator between the electrodes.
Today’s smartphones, power tools, and battery-powered EVs (hybrid EVs (HEVs), PHEVs, or BEVs) currently use lithium-ion batteries with liquid electrolyte (lithium salt) solutions.
Are Solid-State Batteries Better Than Lithium-Ion?
Solid-state batteries have a huge potential to become better alternatives to the current liquid-electrolyte lithium-ion batteries. Solid-state batteries offer several important advantages, namely:
- Higher energy density
- Higher safety
- Shorter charging times
- A wider range of operating temperatures
- Longer lifespan
Let’s discuss these advantages in greater detail in the following sections.
Do Solid-State Batteries Have Higher Energy Density?
Some of the latest research findings this year reveal that solid-state batteries have a much higher energy density compared to conventional lithium-ion batteries. Currently, lithium-ion batteries can have an energy density of 100 to 265 watt-hour per kilogram (Wh/kg). On the other hand, NASA’s latest research revealed that solid-state batteries can reach up to 500 Wh/kg.
So what does higher energy density mean for EV buyers? We can list several small advantages (e.g. you can charge more phones in the car, or sit idly inside the EV with the A/C on, etc.), but the most important benefit is a longer driving range. One of the main challenges to EV adoption is range anxiety – the fear of an EV driver that the drive/traction battery’s charge will run out before the vehicle reaches its destination. As of 2023, the average EV range in the US is 291 miles for a full charge. With solid-state batteries, the average EV driving range can get to almost 600 miles. Toyota is aiming to offer a 900-mile solid-state battery for its future EVs.
Are Solid-State Batteries Safer?
According to a research paper published in the Science Direct Journal last 2022, solid-state batteries are often assumed to be safer than conventional lithium-ion ones. Without the volatile and flammable liquid electrolyte inside, solid-state batteries are less prone to fire and toxic leakages. Electric vehicle fires caused by the lithium-ion battery’s thermal runaway are very hard to put out, particularly because the hydrogen gas produced by the combination of lithium and water (from the firefighters’ hoses) may fuel the fire even further.
Do Solid-State Batteries Charge Faster?
Solid-state batteries charge faster than conventional lithium-ion batteries due to the following reasons:
- Solid electrolytes have lower internal resistance compared to liquid electrolytes.
- Solid-state batteries have higher thermal stability, allowing them to handle higher charging currents.
- Without flammable liquid electrolytes, solid-state batteries degrade slower and manufacturers can design faster EV charging systems with fewer worries about charging-related EV fires and shortening battery lifespans.
Currently, most EVs require 30 minutes of charging time using the fastest level 3 DC chargers to top up their batteries from 10% to 80% charge. In contrast, Toyota’s 1st-generation all-solid-state batteries are aimed at a 10-minute charging time for the same state of charge.
Do Solid-State Batteries Work In Cold Weather?
Over the years, many EV researches have revealed poor EV performance during cold weather. Some of the problems include slow charging, weaker driving power, and shorter driving ranges.
In general, lithium-ion EV batteries operate best at around 70 degrees Fahrenheit (21.5 degrees Celsius), but they can still return excellent results between 50 and 86 degrees Fahrenheit (10 to 30 degrees Celsius). On the other hand, solid-state batteries can theoretically operate efficiently from -40 to 338 degrees Fahrenheit (-40 to 170 degrees Celsius).
Who Uses Solid-State Batteries For Cars?
As of July 2023, no car manufacturer has released a production model that uses solid-state batteries. Last 2020, however, Toyota showcased an LQ Concept prototype EV with solid-state batteries.
The race for EV dominance is in full swing, and several automotive companies are investing heavily in developing solid-state batteries for scalability, practicality, and affordability. Among these companies are:
- BMW
- Ford
- GM
- Honda
- Hyundai
- Mercedes-Benz
- Nissan
- Porsche
- Stellantis
- Toyota
- Volkswagen
Does Toyota Have A Solid-State Battery?
Although Toyota did outfit the LQ Concept EV with solid-state batteries, these cells and packs are still far from the mass-production stage due to several factors like cost, weight, range, and raw material supply. Last June 2023, however, Toyota unveiled its long-overdue BEV strategy, and it includes very promising developments regarding all-solid-state batteries (ASSBs).
Between 2027 and 2028, Toyota plans to release its 1st-generation solid-state battery, which can provide roughly 740 miles of driving range and a 10-minute charging time from 10% to 80%. A 2nd-generation ASSB is currently being researched, and this one is expected to deliver over 900 miles of range.
How Long Does A Solid-State Battery Last?
Currently, many EV manufacturers offer an 8-to-10-year or 100,000-mile warranty for conventional lithium-ion batteries. Although US federal law requires electric car batteries to be covered for a minimum of 8 years, the terms of the warranty may vary among different car companies. For instance, some companies will cover the battery’s replacement only if a complete failure occurs, but some companies like Nissan, Volkswagen, and Tesla will honor the warranty if the battery’s maximum charge capacity falls below 60% to 70% within the warranty period.
The actual lifespan of a conventional lithium-ion EV battery is much longer than its warranty period. For instance, the Tesla Model 3’s battery is designed to last between 10 to 20 years, or 300,000 to 500,000 miles. Tesla has shown that its battery lifespan estimate is not just lip service, as the 2008 Tesla Roadster’s EV batteries reached the end of their useful life this 2023 – after 15 years.
Due to the novelty of the solid-state EV battery technology, tests conducted in 2021 revealed that solid electrolytes were too “brittle” to withstand the same amount of charge and discharge cycles that conventional lithium-ion batteries can handle. However, more recent studies have shown that solid-state batteries can last for 400,000 miles.
Moreover, during this lifespan, solid-state batteries will only show noticeable degradation after about 10,000 cycles. In contrast, conventional lithium-ion batteries start degrading between 2,000 and 3,000 cycles. This means that solid-state batteries will be able to sustain their maximum charge capacity much longer than lithium-ion batteries can.