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Comment by throwaway81523 | Hacker News Reader

This is pretty interesting. It's about battery tech advances (solid state batteries, and high-silicon anodes in li-ion batteries) that will supposedly give a significant jump to power and energy density in EV batteries. Nothing about cost per KWH. Solid state might not be so great in terms of cycle life.

Right now I'm not in the EV market but am impressed by seeing LiFePO4 batteries at under $100 per KWH retail, for possible use at home with off-grid solar. See places like batteryhookup.com if you want some.

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Since we're on an engineering website here, I would like to be pedantic and point out that it's kWh. If you write KWH that would mean Kelvin Watt henry, see https://en.wikipedia.org/wiki/International_System_of_Units. kWh means kilo Watt hours.

A recent AstralCodexTen article pointed out that lithium battery price is 40x lower per kwh than it was in 1992. A few headlines about revolutionary battery technology have turned out to be vaporware; but there really has been a continuous tech revolution going on in the space.

Lithium is problematic in many ways. Security of supply (one of the big disadvantages of ICE is how much of the fuel comes from an unstable part of the world), environmental impacts of mining, the use of child and otherwise exploited child labour.

I have no doubt that electric engines are the future, but we desperately need something better to provide the electricity to them.

Most of the world's lithium is mined in Australia and Chile. If lithium is "problematic", then so is every raw material.

https://pubs.usgs.gov/periodicals/mcs2023/mcs2023-lithium.pd...

Thanks, it looks like I was fooled by scare stories on where it comes from. However there are still issues with who controls it:

https://www.bbc.com/news/world-68896707

and environmental aspects of mining and disposal AFAIK?

Also, contrary to petrol, we have at least a realistic possibility to recycle batteries and thus eventually need less raw earth inputs over time. While with petrol, you need a stable continuous supply.

In response to some of the comments:

For silicon-carbon composite anodes, the challenge in getting apples-to-apples cost per kWh is that while the anode material is more expensive per kg than graphite, it also is much more energy-dense, so you need much less of it. However, to take advantage of the energy density, you need to enlarge the cathode (which brings the lithium). A classic simultaneous equation....

Without giving away proprietary info, it's safe to say the ultimate "value" of the battery (read $ per kWh) is reasonably close to today's Li-ion - for much higher performance.

Since LFP cathode technology is a topic, keep your eyes on LMFP. It is a bit more expensive than LFP, but also carries 15%-20% more energy - so its $ per kWh is lower. Then, if you marry it with a silicon anode, things start to get VERY interesting versus today's Li-ion performance and cost.

There's also potentially big advances to be made in single use but easily recondition-able aluminium-air batteries due to an expanding market. An anecdote I've heard is a lot of R&D is focused on these at the moment as they have a higher energy to weight ratio compared to lithium chemistries so are idea for "disposable" use cases such as suicide bomb drones. There's also the more pedestrian idea of automated battery swap stations.

On a similar note, thermal imagers have got shockingly cheap recently, 50KPixel cube camera modules are available for <$200 and <$800 for the 0.33MPixel version. I recently picked up an integrated module with a 24x32 pixel sensor, LCD, uC and LiPo for £30n and it can "see" someone step out from behind a wall at a distance of 3 meters, ideal for my use case (airsoft!)

> An anecdote I've heard is a lot of R&D is focused on these at the moment as they have a higher energy to weight ratio compared to lithium chemistries so are idea for "disposable" use cases such as suicide bomb drones.

You could use normal fuel-burning engines for that, I'd suppose. Or rockets, depending.

> , 50KPixel cube camera modules are available for <$200 and <$800 for the 0.33MPixel version

The 50k case is not that recent (FLIR Lepton). Not sure about the 0.33MP. The 24x32 is very cheap and as you say, has enough res for some ok applications. I've been intrigued by it and wondered why FLIR seems to still have a monopoly over higher res detectors.

It could make sense for you to consider an EV with bi-directional charging. For off-grid solar, you can charge your truck/car/EV for free or/and extend your off-grid battery by using your car to de/uncharge it for your home.

A 100kWh battery can help you out when you come back home if you know you can charge it the next day.

The normal price when buying locally or from china seems to be 200$/kwh.

But with a higher estimated lifespan, an estimated a cycle count 2-5x that of traditional li-ion batteries, in paet due to it not having moving parts, $200/KwH seems reasonable vs $100/KwH if it lasts more than 2x as long as a product of similar other specs.

Yoshino has a large portable one on the market, 4000W, 2511Wh, though it's a bit pricey as it's new technology.

> $200/KwH seems reasonable vs $100/KwH if it lasts more than 2x as long as a product of similar other specs

I think that's highly dependent on the expected life of those cells in absolute terms. If I'm buying a consumer product and a $100/kWh battery cell will last 10 years, but a $200/kWh battery cell will last 20 years, I'll go with the $100 one every time.

Why? Because in 10 years, with inflation and advancements in battery technology, I'll probably be able to buy a replacement 10 year battery for $40 in today's money, for a total of $140 instead of $200. I'm also lowering my risk exposure in case something happens to the battery, it only needs to survive 10 years instead of 20.

*Exact figures made-up on the spot.

Using actual numbers, if your cellphone battery lasts 2 years of nominal use before noticable degrading, you're looking at 4-10 years, but also contributing less e-waste to the world.

I doubt cell phone batteries are a significant part of the battery waste stream, compared to EV and utility scale batteries. If they only went back to phones with easily swappable batteries and used a commodity form factor, most users would probably prioritize energy density over cycle life.

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