In the past few days, two big shots in the new energy vehicle industry have been arguing on Weibo about batteries.
The whole thing started when SmartSelf promoted their new car L6, claiming to have developed "the industry's first nearly 900V ultra-fast charging solid-state battery".
Ignore all the fancy words upfront about 900V and super-fast charging; the real deal here is the "solid-state battery."
Solid-state batteries have been talked about for a while, but since no one had really seen the real deal before, it felt like a distant dream.
After Zhi Ji made some bold statements, Zhao Changjiang from the neighboring company couldn't sit still, saying, "Anyone promoting semi-solid-state vehicle batteries at this time is just playing word games." (He later deleted the post.)
Well, things got spicy real quick.
Even though he didn't mention Zhi Ji by name, Zhi Ji CEO Liu Tao jumped right into the fray, retorting across the ether: "We're not good at playing word games; Zhi Ji definitely has top-notch products." Just typing wasn't enough for Liu Tao; he even hosted a live broadcast to show off their solid-state battery factory to everyone.
Neck Brother wouldn't miss out on this kind of scoop for sure. I'm curious to see if Zhi Ji really has some top-notch stuff.
The livestream this time isn't short, it's about an hour and a half long. The livestream is taking place in the laboratory of battery supplier Qing Tao Energy, and the main content is about explaining how the solid-state battery that Zhi Ji is about to use is made.
We've stuck around for the entire livestream, so is Zhi Ji really just playing word games?
I think so, but not entirely.
To put it in perspective, let's first talk about what solid-state batteries are.
The lithium batteries commonly found in cars today are liquid-state batteries, consisting of four main components: the cathode, anode, electrolyte, and separator.
In lithium-ion batteries, the movement of lithium ions through the electrolyte from the positive electrode to the negative electrode during charging is called charging, and the opposite process is called discharging. Solid-state batteries, as the name implies, replace the liquid electrolyte with a solid one.
The advantage here is primarily the sky-high energy density of the battery. By ditching the electrolyte that tends to get unstable under high voltage, solid-state batteries can employ more robust high-voltage materials on both the cathode and anode. For instance, while liquid batteries typically use graphite for the anode, solid-state batteries opt for metallic lithium, which boasts roughly 10 times the specific capacity of graphite.
In addition, solid-state electrolytes have a smaller volume, allowing batteries to be lighter and thinner, resulting in higher energy density. Contemporary Amperex Technology's (CATL) Kirin battery has an energy density of 255Wh/kg, which is already relatively high among liquid batteries, while solid-state batteries can easily achieve 500Wh/kg, doubling the capacity. Apart from energy density, another major advantage of solid-state batteries is their stability. Liquid electrolytes are inherently flammable, so if the battery is damaged by external forces, it can lead to thermal runaway, potentially causing smoke, fire, or even explosions.
In comparison, solid-state batteries are just incredibly robust.
The solid electrolyte inside them cannot burn, is resistant to high temperatures and corrosion, basically eliminating the risk of spontaneous combustion.
Clearly, solid-state batteries address the two major pain points of electric vehicles: range and safety, making them a perfect solution, hence becoming the focus of research.
Domestic companies like NIO, SAIC, GAC, CATL, as well as foreign ones like Toyota, Nissan, BMW, and Daimler, all claim to be developing solid-state batteries.
But, this thing isn't as easy to crack as it seems. Solid-state batteries are still just lab products at the moment, with plenty of issues yet to be resolved. For instance, the ionic conductivity of solid-state electrolytes is much lower than that of liquid electrolytes, and the high impedance of the battery also affects lithium ion transport, leading to increased internal resistance and limited charge-discharge cycles. Without overcoming these hurdles, commercialization is out of the question. Therefore, the industry's outlook on the timeline for solid-state battery mass production is quite conservative. Domestically, there's talk of it not happening until 2030, while Toyota overseas seems confident, claiming they can achieve mass production by 2027. However, considering they haven't even figured out liquid batteries yet and have already delayed several times (originally they said mass production could start in 2022), there are big question marks hanging over their heads.
Since it's so tricky and no one has nailed it yet, well, neither did Intel. Yeah, you can't rush perfection. Transitioning from liquid to solid state has to be done gradually.
Since going all solid-state wasn't cutting it, engineers came up with a trick: replace some of the electrolyte with solid material, creating something in between full solid-state and liquid.
And that's the new thing Intel is working on.
During the livestream, representatives from Qingtao Energy (a battery supplier) showcased their first-generation product, the semi-solid-state battery, which will be used in the upcoming Zhiqi L6. They announced plans to develop second and third-generation products in the coming years, with the ultimate goal of achieving a fully solid-state battery.
The focus of these three generations of upgrades is to minimize battery defects and reduce size. For instance, while the first-generation battery still requires a separator, the second generation will eliminate this component, and the third generation will feature even fewer materials.
In essence, true solid-state batteries are on the horizon for everyone to look forward to.
The semi-solid state of it does incorporate solid electrolytes. However, due to the insufficient density of the solid, there are gaps within the electrolyte, which affect the transport of lithium ions. To address this, they add 10% of a wetting agent to fill these gaps with liquid. Thus, the entire electrolyte is neither "solid" nor "liquid," but rather in a viscous state.
Then, they apply a solid electrolyte layer, approximately 10 micrometers thick, onto the surface of the positive electrode. This layer, primarily composed of inorganic materials, aims to enhance the stability of the high-nickel positive electrode material.
The final battery performance has certainly seen significant improvements. According to the CEO of ZhiJi, the four-wheel-drive model equipped with this battery can run for over 1000 kilometers. So, is this semi-solid battery considered solid-state?
Actually, someone asked a similar question a few days ago on ZhiJi's official Weibo account, and the official response was quite cryptic: "Is a white horse a horse?" Well...
Let's see what Zhiji is promoting - "Almost 900V Ultra-Fast Charge Solid-State Battery". They added "almost" before a bunch of words. Well, well, seems like they're keeping a card up their sleeve.
But you know what? When it comes to semi-solid-state batteries, Zhiji isn't the first one to take a bite out of the crab. Last December, Li Bin showcased NIO's 150-degree battery pack's endurance during a live stream, and the car eventually covered 1044 kilometers.
That battery pack is a semi-solid-state battery, boasting an energy density of 360Wh/kg in its cells.
Neck Brother also consulted with several industry insiders. Currently, semi-solid-state technology is quite mature, but the main issue with mass production is the high cost, leading to expensive prices.
NIO's 150-degree battery pack is only available for lease, not for sale. NIO executives have previously disclosed the cost of this battery pack, which is equivalent to the price of a single ET5 (starting at 298,000 RMB). Moreover, mass production is still not feasible, with only 1000 units produced this year.
For Zhiji, the semi-solid-state battery intended for the L6 model is also unlikely to be cheap. Neck Brother speculates that it might be offered as an optional configuration. If the car is priced around 200,000 RMB, opting for a semi-solid-state battery could push the price close to 500,000 RMB.
As for whether this speculation holds true and how well Zhiji's battery performs in reality, these questions will be answered once the new car is launched and tested.
