Progress toward 3D printing lithium-ion batteries | Hacker News Reader

Progress toward 3D printing lithium-ion batteries

b3dgeable.com

43 pointsteawithcarl12 comments

Wow, that's quite something.

I really feel the tech around batteries needs particular focus, as the one thing computing technology seems to lag on is battery life - I dream of a time where I can charge my laptop once a year and not have to worry about it otherwise.

Perhaps 3D printing of batteries will offer easier iteration on new ideas?

More likely, they'll be able to build unique shapes for batteries that will allow cramming more battery into awkward spaces.

Battery life only sort of bugs me, the real issue I have with modern batteries is longevity.

Once a typical Li-ion battery is a few years old it might as well be worthless, it will hold only a fraction of the original charge it could when it was new and that amount will continue to drop over time. If we could build batteries with even 80% of the storage density of Li-ion but would retain 90% of that capacity over 10 years I'd be pretty happy.

That's for a large part due to the charging speed itself. If you charge at the maximum allowed current your battery will have the shortest longevity. Most chargers advertise on the capability to charge fast, but for a lot of battery chemistries it comes with that trade off. If you have the habit of charging over night I'd suggest to buy a slow charger or trickle charger. The slowest (optimum longevity) are typically "40 rate" which means (I'm simplifying here) the charge current is 1/40 the Max capacity current and takes about 40 hours to charge.

Note: don't go cheap by buying Chinese crap for battery chargers, especially Li chemistries. Best case: works as advertised. Worst case: electrocution or house goes up in flames.

The Lewis lab's main contribution here is the scale and precision of 3D printing. These batteries are not immediately useful (although there are sensors and other electronics that are an order of magnitude smaller than the batteries that power them, and in the future micro-scale batteries could overall reduce the size of these electronics). They are not powerful or robust, but they are precisely assembled. This type of 3D printing will enable future miniaturization of electronics and be especially useful at the interface of electronics and biology. For instance, current 3D printers have resolution several orders of magnitude above the scale of features in tissues. Increasing the resolution of 3D printing enables tissue engineering at a scale similar to actual biological features. Batteries are just a flashy and potentially useful application of this fundamental printing technology.

I wonder how "sturdiness" scales. What happens when you drop or bang a battery with such tiny features? Obviously they are very weak, but they also have very little mass.

I generally count on HN to have someone with experience in any given field. Today I call on those with experience scaling structures into the larger micron ranges.

force from acceleration scales linearly with mass. mass, however, scales cubic with size: something at 1/10 scale is 1/1000 the mass.

surface scales square with scale (something at 1/10 scale has 1/100 surface or cross section surface)

with miniaturization with factor x you get 1/x^3 mass and 1/x^2 cross section surface. as a result stresses (Force/Surface) becomes 1/x less on a given surface for acceleration.

(on mobile, edited a few times)

Obviously a typo in the title. 300µm in the article.

Might not be the right place to post this, but the twitter notification for this article says "300m", I think they made them a bit smaller than that.

That's because they use a broken string type.

https://news.ycombinator.com/item?id=6807524

(Sorry)

What's a milli-micro?

The correct measurement is µm - micro meter.

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