Solid-State Battery – What is It and How Does It Relate to a Cars? – Electric cars are constantly improving in terms of range, performance, and charging time. However, there is still a lot of room for improvement in the various weaknesses of the electric car. Although the number of hybrid cars is likely to increase rapidly, fully electric vehicles are not ready to overtake internal combustion engines.
That’s because most EVs and hybrids rely on electric motors powered by lithium-ion batteries, using the same technology used in smartphones and laptops. Essentially an evolution to chemical batteries, lithium-ion batteries do well in EVs, but there are better solutions.
The use of liquid electrolytes in lithium-ion batteries has several drawbacks. The capacity and ability to deliver peak payloads decrease over time. In addition, lithium-ion batteries emit a lot of heat, requiring a heavy cooling system to be integrated into the design. And thanks to the flammable liquid they contain, lithium-ion batteries can catch fire or even explode if damaged in an accident.
Over the last few years, carmakers have started to call solid-state batteries their next EV breakthrough, usually citing great performance and range at the same time. So, what makes solid-state battery technology so good for EVs, how does it work?
What is a solid-state battery?
Put simply, solid-state batteries use solid electrolytes as opposed to polymeric liquids or gels found in today’s lithium-ion batteries and can be ceramic, glass, sulfite, or solid polymer.
Apart from solid electrolytes, solid-state batteries function much like lithium-ion batteries, as they contain electrodes (cathode and anode) separated by electrolytes that allow charged ions to pass through.
How do solid-state batteries work?
Similar to a regular battery. The flow of ions triggers a chemical reaction between the battery materials called ‘Redox’ in which, when discharged of power, oxidation occurs at the anode to make a compound with free electrons, which conducts electrical energy, and reduction at the cathode which sees the compound gain electrons and thus stores power. . When the battery is charged, the process is reversed.
Just like lithium-ion batteries, when carrying power in a solid-state battery, aka discharging, positively charged ions travel through the electrolyte from the negative electrode (anode) to the positive electrode (cathode). This causes a positive charge to form at the cathode which attracts electrons from the anode. But because electrons cannot travel through the electrolyte, they must travel across the circuit and thus send power to whatever is connected to it.
During charging, the opposite occurs with ions flowing into the anode building up a charge that sees electrons being pulled there across the circuit from the cathode. When no more ions flow to the negative electrode, the battery is considered fully charged.
Solid-state batteries have been around for some time, but are only used for small electronic devices such as RFID tags and pacemakers and are not currently rechargeable. Thus, work is being done to enable them to power larger devices and recharge.
What makes solid-state batteries the next big thing?
Thanks to solid electrolytes which have a smaller footprint, solid-state batteries promise about two to ten times the energy density of lithium-ion batteries of the same size. This means a more powerful battery without extra space or a more compact battery pack without sacrificing power. That means a more powerful electric car and more mileage or a more compact, lighter EV. They are also expected to charge faster.
Better efficiency and energy density mean solid-state batteries don’t require cooling and control components like lithium-ion batteries, and that means a smaller overall footprint along with more chassis freedom and less weight. It’s no surprise that solid conditions are cited the most by performance car manufacturers; Bentley saw technology as the primary way to make electrification work for them.
Safety is another advantage that solid-state batteries offer. Exothermic reactions in lithium-ion batteries can cause the battery to heat, expand, and have the potential to break, spilling flammable and hazardous electrolytes; in some cases, this causes a small explosion. Having solid electrolytes effectively alleviates this problem.
Lastly, the use of solid-state electrolytes means batteries can withstand more discharge and charge cycles than lithium-ion batteries because they don’t have to experience electrode corrosion caused by chemicals in liquid electrolytes or buildup of solid layers. in electrolytes that destroy battery life. Solid-state batteries can be recharged up to seven times as much, giving them a potential ten-year lifespan compared to several years lithium-ion batteries are expected to last effectively.
You may be wondering why solid-state batteries aren’t used in EVs because they are considered a panacea for lithium-ion battery problems. But the challenge with solid-state batteries is that manufacturing them is extremely difficult on a large scale.
Not only is it currently too expensive to push into commercial use, but there is also still a lot of work to be done to get it ready for mass-market use, especially in EVs.
Currently, there is still a need to find the right atomic and chemical composition for a solid electrolyte that has the right ionic conductivity to generate sufficient power for an EV motor.
That’s why we started the benefits of solid-state batteries with the word ‘can’ because they haven’t proven themselves in the real world in consumer gadgets, let alone electric cars.
Getting the solid electrolyte right is very important because it is a precursor to enabling the use of lithium anodes, which can generate more lithium ions and thus more energy. Solid-state electrodes are considered the solution to the problem of damage to needle-like structures called dendrites that form on the anode when charged.
Despite these challenges, the allure of solid-state batteries is clearly strong, as Toyota, Honda, and Nissan team up to create a Libtec consortium to develop solid-state batteries, with the first to be expected to unveil a solid-state battery-powered car at the Olympics. Tokyo this year.
And there are academic institutions, battery makers, and materials specialists who are studying how solid-state batteries can be developed into next-generation resources for mass use. There’s no shortage of thrill and interest in solid-state batteries.
However, Toyota doesn’t expect to manage mass production of solid-state batteries until the middle of this decade. And other automakers like Volkswagen don’t expect to have solid-state batteries ready for cars to use until at least 2025.
IBM and Daimler work together to better understand battery technology. “We need to find fundamentally different chemicals to create future batteries,” Katie Pizzolato, director of applications research at IBM, said. “Quantum computing allows us to peek effectively into the chemistry of batteries, to better understand the materials and reactions that will give the world a better battery.”
The maker of vacuum engines and other air blower technologies, Dyson, has planned to build a solid-state battery electric car by 2021. But its car plans were discontinued last fall, although it aims to keep working on battery technology.
Fisker Inc, the reincarnation of the collapsed Fisker Automotive, previously expressed high ambitions to have a car running on solid-state batteries ready for 2020. But at this year’s Consumer Electronics Show, they only showed off the Ocean SUV, which is powered by lithium-ion batteries. ; no news about solid-state battery setup.
So, while there’s a lot of activity surrounding solid-state battery development, it’s highly unlikely you’ll see an EV powered by it anytime soon.
As one of the largest lithium-ion battery makers in the world, Panasonic has an edge in the battery game. However, solid-state batteries are estimated to have ten years left for commercial use.
It co-owns the Tesla Gigafactory and supplies batteries for the Tesla car, and it reckons that improvements to EV batteries in the short term will come from further development of lithium-ion batteries.
Instead of going the solid-state path, Tesla is working to improve the performance of lithium-ion batteries, with its last year touting new chemistry that could power EVs for more than a million kilometers.
Given the improvements to lithium-ion batteries and the range that can be extracted from them, as well as how they are already being mass-produced, it’s unlikely that we’ll see them put out of solid-state batteries any time soon.
But solid-state batteries do look like the future power source for electric cars, the road to them may be longer than expected.
This article originally appeared on carmagazine.co.uk.