Solid-state batteries have been considered a good source of energy for electric vehicles and electronics for many years, but by 2022 we still haven't seen them. During this period, a variety of battery technologies have emerged, but none can surpass solid-state batteries in terms of energy density, lifespan, and safety. In this issue, let’s get closer to solid-state batteries and electric vehicles.
Like clean energy, people have been eager to make major breakthroughs in battery technology. New solid-state batteries not only have good energy density, long life, higher safety and lower costs, but can also minimize fossil emissions. Fuel use. The most widely used now is definitely lithium-ion battery , but it also has some shortcomings. First, lithium-ion batteries require a battery management system to prevent them from being overcharged or overdischarged. This significantly increases manufacturing costs and structural complexity. Secondly, as the number of charging times increases, lithium batteries will undergo irreversible aging. And they are very heavy, accounting for almost one-third of the total weight of the entire device. Finally, lithium batteries are expensive to make, which is why researchers are constantly looking for new battery technologies.
Lithium-ion battery
Lithium battery consists of an anode, a cathode, a film made of polymers that can act as a physical separator and insulation, and an electrolyte that can chemically react with the anode and cathode. The charged particles pass through the electrolyte between the electrodes. Flow creates an electric current. However, liquid electrolytes are easy to burn, have the risk of leakage, and are easily decomposed under high pressure. Solid-state batteries use solid electrolytes and do not contain any liquid, so they are safer to use. If a liquid electrolyte battery is punctured, it is likely to explode.
In contrast, solid electrolytes are not only non-flammable, but can still operate normally without leakage or explosion accidents even when punctured. In addition, the energy density of solid-state batteries is almost 2.5 times that of lithium batteries. The weight of lithium batteries is about 250-270WH/KG, which means that solid-state batteries are lighter and store more energy. Researchers also found that the charging time of solid-state batteries is 4-6 times faster than that of lithium batteries. This is definitely good news for consumers. After all, charging time is also an important indicator when considering electric vehicles.
Solid-state battery working diagram
In 2021, QuantumScape announced that they had developed a solid-state battery with an energy density of 1000WH/L. It can be charged to 80% in 15 minutes and weighs about 380-500WH/KG. This battery is expected to be mass-produced in 2024. At the same time, Toyota and Panasonic have also jointly developed a solid-state battery. Its cruising range is twice that of Toyota's current lithium battery, but this battery may not be mass-produced until after 2025.
These battery technologies sound good, but it will take a long time to enter the market. So what is the development of solid-state batteries at this stage? In April 2022, Nissan announced its first solid-state battery solution. They plan to launch a new production line in Yokohama . However, this battery is still in the prototype stage. Its size is only about 2 cm and is single-layered. The capacity is 20 mAh. In order to improve battery performance, Nissan collaborated with University of California to evaluate hundreds of thousands of materials to find those that are more suitable for solid-state batteries. Nissan predicts that by 2028, they can control the price of solid-state batteries to around US$75 per kilowatt-hour. After mass production, the price can even be reduced to US$65 per kilowatt-hour.
Nissan solid-state battery
In January 2022, Quantum Scape announced that their single-layer lithium metal solid-state battery can control the charging heating temperature between 25-45 degrees, and the battery can be fully charged in 15 minutes. After 400 cycles, the battery The capacity can still be maintained at about 80%. This is great data, but you must know that when using a DC fast charger, it can only charge the lithium battery to 80% in 30 minutes. If each charging cycle can travel 482 kilometers (300 miles), the total driving range of 400 cycles is 192,800 kilometers (120,000 miles).
Although the total mileage data is excellent, the total number of cycles has not reached the industry standard of 800-1000 times. In order to achieve this goal, Quantum Scape has been trying to increase the number of battery layers. In May 2022, they announced that they had developed a 16-layer solid-state battery capable of 500 charge and discharge cycles. But this is not enough. Quantum Scape has invested in multiple production lines and plans to increase production capacity to 3,700 pieces per week. This is because if you want to fully popularize solid-state batteries, in addition to technical factors, mass production is equally important. Therefore, if solid-state batteries are still unable to be mass-produced before 2030, it will be difficult to make greater achievements.
Quantum Scape solid-state battery
In addition to solid-state batteries, there are many different battery technologies that are also trying to break through the bottlenecks caused by energy density, safety and manufacturing costs. For example, researchers at Drexel University found that injecting sulfur into lithium batteries can effectively reduce the amount of cobalt, nickel and manganese used. This technology mainly uses carbonate as the electrolyte. If the problem of sulfur volatilization can be solved, theoretically, the cycle life of this battery can reach about 4,000 times. Its lifespan is almost 10 times that of QuantumScape solid-state batteries, and its battery capacity is three times that of lithium batteries and even 20% higher than solid-state batteries. However, this lithium-sulfur battery is not perfect. Its manufacturing cost is very high. At this stage, the cost per kilowatt hour is as high as $200.
In addition, there is a niobium material battery that supports a 6C charging rate, can be charged to 80% in 10 minutes, and can still retain 80% of the battery capacity after 3,000 cycles. This data is almost 8 times that of QuantumScape solid-state battery. Of course, we should not forget the new generation 4680 battery of Tesla . Compared with the traditional 2170 battery, its capacity has increased by 6 times, the cruising range has increased by 16%, and the battery cost per kilowatt hour has dropped by 56%. The launch time of solid-state batteries is still unknown, and by January 2022, 1 million 4680 batteries have been manufactured in the California factory. Tesla also plans to use them in the latest Model Y model, although it has not Those advantages of solid-state batteries, but also minimizing manufacturing costs and improving driving range. For ordinary consumers, this is completely sufficient.
4680Battery
These new battery technologies mentioned above are weakening the solid-state battery market. So, what exactly do we need most? The publicity of solid-state batteries seems to be a bit exaggerated. Niobium batteries have excellent performance, but we don’t know how long it will take to enter the market. Lithium-sulfur batteries are still in their early stages, and cost is their biggest enemy. The 4680 battery has been put into mass production and may occupy a wider market space.
So do you think solid-state batteries will be successful?
