什么是固态电池？

从理论上讲，固态电池优于电动汽车中最常用的锂离子电池，但它们还没有准备好接管。https://cdn.motor1.com/images/mgl/eoRybE/s3/quantumscape-solid-state-battery.jpg

美国东部时间2024年1月16日下午1：32

作者：Andrei Nedelea

电动汽车很棒，但如果它们不必拖着一个又大又重的电池组，那就更好了。使电动汽车电池更小、更安全、更密集是所有制造商的首要任务，但每一种电池本身都是一个挑战，我们在过去十年或更长时间里只看到了渐进式的进步。

如今，大多数电动汽车中的锂离子电池可以追溯到 1991 年推出的概念，它们主要用于笔记本电脑等消费电子产品。通过渐进式改进，它们变得足够好且便宜，足以成为汽车牵引电池的首选解决方案。然而，尽管今天有数十亿美元投入到电池研究中，但这些限制并不容易克服，汽车制造商正在寻找一种突破性的解决方案，以解决锂离子或新型锂聚合物（LFP）电池的所有问题。

固态电池可能是该行业正在寻找的突破口，但目前尚不清楚它们何时会进入量产车。它们已经用于智能手表甚至医疗植入物等小型设备，但我们还没有看到它们用于许多大型应用。

但即使技术问题得到解决，仍然存在固态电池成本问题。预计它们的价格将比锂离子电池贵三到四倍左右。

为什么固态电动汽车比锂离子或磷酸铁锂更好？https://cdn.motor1.com/images/custom/assb-01-en.jpg

与目前使用液体或凝胶电解质的电动汽车电池不同，固态电池使用固体电解质。在当前一代锂离子电池中，锂盐溶解在溶剂中，产生挥发性液体，淹没整个电池，而在固态电池中，电解质可以是陶瓷、硫化物或其他类型的固态材料。它的作用与允许电子在电池的阴极和阳极之间流动的目的相同。

通过消除易燃的液体电解质，固态电池在发生事故时变得更加安全。固态电池不仅能够更好地保持其形状，而且即使它们被破坏，由于它们对高温的耐受性更高，导致电池组大规模起火的可能性也要低得多。因此，电池短路的可能性也要低得多。

这也减少了热失控的机会，这是一种连锁反应，电池单元会过热并可能燃烧，这将从一个电池组扩散到另一个电池组，最终消耗整个电池组。

固态电池的能量密度是当前锂离子电池的两倍以上。这意味着在相同容量下，电动汽车的电池组将需要更少的电池单元，并且电池组将更轻，从而提高车辆的续航里程、性能和操控性。该电池组在物理上也更小，因此它不必占据汽车的整个底部，从而可以改善内部空间的使用，并为乘客或货物提供更多空间。

使用固态锂金属电池等设计，电池本身更短，因此即使在电池垂直放置的电池组中，您仍然可以使电池组更薄。

锂离子电池组充电导致的反复热循环导致的电解质降解是当前电动汽车电池随时间推移而失去容量的一种方式。固态电池具有更稳定的电解质，因此它们应该持续更长时间，同时保持更大的容量。

固态电池的另一个优点是，当定期快速充电到 100% 时，它们可能会更快地充电并且不会损坏。目前的锂离子电池希望保持在 20% 到 80% 的充电状态之间，以尽可能长的使用寿命，但这不是固态电池的要求。https://cdn.motor1.com/images/custom/screenshot-2024-01-12-at-174946.png

改善寒冷天气性能是固态更好的另一个领域。固态电池可以承受更宽的温度范围，并且它们受外界温度的影响应该较小。这意味着它们可以在冰点温度下保留更多的电荷，并且在相同条件下也能实现更高的充电速度。

拥有最先进的内部固态电池研究项目的汽车制造商丰田表示，与尚未发布的下一代锂离子和磷酸铁锂电池相比，它应该提供20%的续航里程。它应该允许电动汽车超过620英里的续航里程，并在大约10分钟内从10%充电到80%。

固态电池何时进入电动汽车？https://cdn.motor1.com/images/mgl/kv0Oe/s1/mercedes-benz-ecitaro.jpg

丰田在透露其固态电池计划时有些神秘。在其电池驱动的汽车推出路线图中，丰田透露，它的目标是到 2028 年将固态电池用于商业用途（尽管最近的一份报告表明它们可能会更早到来）。该制造商证实，第一批固态电池将引入其混合动力汽车，而不是全电动汽车。

就像丰田一样，日产也发誓要在2028年之前推出固态电动汽车，并且它已经建立了一个原型生产设施，能够在内部制造电池。现代汽车最近在美国申请了全固态电池的专利，并计划在2030年之前将这些电池投入生产电动汽车。

宝马正在与Solid Power合作开发固态电池，但其目标是最终将开发转移到内部，而不是依赖第三方。这家巴伐利亚汽车制造商将在 2025 年推出一款名为 Neue Klasse 的全新定制电动汽车平台，但直到本十年末才会配备固态电池。https://cdn.motor1.com/images/mgl/pE8L1/s1/mercedes-benz-ecitaro-uses-all-solid-state-batteries-from-bluesolutions.jpg

东风是一家致力于固态电池的汽车制造商，其 2023 年在中国推出的新型电动城市汽车 Nammi 01 旨在支持固态电池，最初听起来像是要推出它。然而，成品车有两个可用的电池组，但都不是固态的。

梅赛德斯-奔驰在 2021 年和 2022 年为数十辆开往德国不来梅市的 eCitaro 电动城市公交车配备了固态电池组。它们采用法国Blue Solutions生产的固体电解质的441kWh锂聚合物电池。这些巴士今天仍在不来梅使用，梅赛德斯指出，尽管它仍然提供固态 eCitaro，但它对新一代 NMC 电池的需求越来越大。

固态电池推出的时间表尚不清楚，但到本世纪末应该会有一些商用型号。固态技术的采用过程将受到我们无法预料的潜在突破的刺激。液体电解质电池的不断改进和成本降低也有可能使其保持相关性，即使可行的固态电池解决方案进入市场。这将是一个比其他任何事情都更重要的成本问题。

原文阅读

What Are Solid-State Batteries?

Solid-state batteries are, on paper, superior to the lithium-ion batteries most commonly used in EVs, but they're not ready to take over yet.

Jan 16, 2024 at 1:32pm ET

By: Andrei Nedelea

Electric vehicles are great, but they would be even better if they didn’t have to lug around a big and very heavy battery pack. Making EV batteries smaller, safer, and more power-dense are top priorities for all manufacturers, but each is a challenge in its own right, and we’ve only seen incremental advancements over the last decade or more.

The lithium-ion batteries that are in most EVs today can be traced back to a concept introduced in 1991, and they were developed primarily for use in consumer electronics such as laptops. Through incremental improvements, they became good and cheap enough to be the go-to solution for automotive traction batteries. However, even though billions are being poured into battery research today, the limitations aren’t easy to overcome, and automakers are looking for a breakthrough solution that will fix all the problems of lithium-ion or the newer lithium polymer (LFP) batteries.

Solid-state batteries might be the breakthrough that the industry is looking for, but it’s still unclear when they will reach production vehicles. They are already used in small devices such as smartwatches and even medical implants, but we’ve not seen them used in many larger applications yet.

But even once the technical issues are ironed out, there will still be the issue of solid-state battery cost. They are expected to be around three or four times more expensive than lithium-ion batteries.

Why Are Solid-State Better EVs Than Lithium-Ion Or LFP?

Unlike current EV batteries, which use either a liquid or a gel electrolyte, solid-state batteries use a solid electrolyte. In a current-gen lithium-ion battery, lithium salts are dissolved in a solvent, resulting in a volatile liquid that floods the entire cell, while in solid-state batteries, the electrolyte can be either a ceramic, a sulfide, or some other type of solid-state material. It serves the same purpose of allowing electrons to flow between a battery’s cathode and anode.

By eliminating the flammable liquid electrolyte, solid-state batteries are made much safer in the event of an accident. Solid-state cells will not only be able to hold their shape better, but even if they are breached, the chance that it will result in a massive battery pack fire is much lower thanks to their higher tolerance to high temperatures. As a result, the chance of a cell short circuit is also much lower.

This also reduces the chance of thermal runaway, which is a chain reaction where battery cells will overheat and potentially combust, and this will spread from one cell to another, eventually consuming the entire pack.

Solid-state batteries can be over twice as energy-dense as current lithium-ion batteries. This means an EV’s battery pack would require fewer battery cells for the same capacity, and the pack would be lighter, thus improving the vehicle’s range, performance, and handling. The pack would also be physically smaller, so it wouldn’t have to take up the entire bottom of the car, thus allowing for improved interior use of space and more room for passengers or cargo.

With designs like the solid-state lithium-metal battery, the cells themselves are shorter, so even in a battery pack where the cells are placed vertically, you can still make the pack thinner.

Electrolyte degradation due to repeated thermal cycles caused by charging a lithium-ion battery pack is one way current EV batteries lose capacity over time. Solid-state batteries have a much more stable electrolyte, so they should last much longer while maintaining more capacity.

Another advantage of solid-state batteries is that they can potentially charge quicker and not get damaged when regularly fast-charged to 100 percent. Current lithium-ion batteries like to be kept between 20 and 80 percent state of charge for the longest possible life, but this would not be a requirement with solid-state.

Improved cold weather performance is another area where solid-state is better. Solid-state batteries can withstand a wider range of temperatures, and they should be less affected by outside temperatures. This means they would retain more charge in freezing temperatures and also allow for higher charging speeds under the same conditions.

Toyota, the automaker with the most advanced in-house solid-state battery research project, says that it should offer 20 percent more range compared to its still unreleased next-gen lithium-ion and lithium iron phosphate batteries. It should allow EVs to exceed 620 miles of range, and charge from 10 to 80 percent in about 10 minutes.

When Are Solid-State Batteries Coming To EVs?

Toyota has been somewhat cryptic when it comes to revealing its solid-state battery plans. In its battery-powered vehicle rollout roadmap, Toyota revealed it aimed to have solid-state batteries ready for commercial use by 2028 (although a recent report suggests they may arrive even sooner). The manufacturer confirmed that the first solid-state batteries will be introduced in its hybrid vehicles, not full EVs.

Just like Toyota, Nissan has also vowed to launch a solid-state EV by 2028, and it already has a prototype production facility up and running capable of making the batteries in-house. Hyundai recently filed a patent for an all-solid-state battery in the US, and it plans to put these batteries into production EVs before 2030.

BMW is working with Solid Power to develop solid-state batteries, but its goal is to eventually move development in-house and not rely on a third party. The Bavarian automaker will launch a brand new bespoke EV platform called Neue Klasse in 2025, but it won’t feature solid-state cells until closer to the end of the decade.

Dongfeng is an automaker working on solid-state batteries, and its Nammi 01, a new electric city car introduced in China in 2023, was designed to support a solid-state battery, and it initially sounded like it was going to launch with it. However, the finished production car has two available battery packs, but neither is solid-state.

Mercedes-Benz equipped a few dozen eCitaro electric city buses destined for the German city of Bremen with solid-state battery packs in 2021 and 2022. They feature 441 kWh lithium polymer batteries with a solid electrolyte produced by Blue Solutions in France. These buses are still in use in Bremen today, and Mercedes notes that even though it still offers a solid-state eCitaro, it’s seen more demand for its new generation NMC batteries.

The time frame for solid-state battery rollout is unclear, but there should be a handful of commercially available models by this decade's end. The process of solid-state adoption will be spurred by potential breakthroughs that we can’t anticipate. There’s also a chance that the constant incremental improvements and lowering of costs brought to liquid electrolyte batteries will keep them relevant even once a viable solid-state battery solution hits the market. It will be a question of cost more than anything else.