I’ve been reading up on active battery-powered implants for some time now and I understand the risks associated: the venting of gases, explosions, etc.
I understand that CO2, CO, and hydrogen are among the gases lithium batteries can vent under certain conditions. Does anyone know of any literature that explores what would happen if such gases were leaked into the body in a subdermal implant setting?
you are my favourite serial killer WIP
no… what an absurd accusation…
ok bundy, ok
I think the only existing cases are grinders noticing it bulging soon enough and taking it out before the coating fails.
You might want to explore scuba or deep sea diving. Both can lead to gas absorption and are very very well documented. Granted it’s not exactly the same, but you might be able to glean some insights.
Interesting, I hadn’t thought about scuba diving. I’ll do some reading on that. Thanks.
The issue becomes oxidation and chem reactions with water and other bodily fluids. Hydrofluoric acid can be one of the many resulting chemicals produced… it’s not pretty.
There is a german startup with a new Iron-Salt Redoxflow battery in development for home battery storage.
The main ingredients are Iron, Salt and Water. This sounds less dangerous, even if a sealing is leaky.
I think the biggest problem would be the size.
More infos:
https://voltstorage.com/en/iron-salt/
I imagine a battery where you need to pump liquid isn’t ideal for in body use.
I suspect the target for those just like Iron Air batteries is for long term discharge of energy for grid scale applications where lithium ion can only supply for 4 hrs.
There are even some already for medical purposes. (small pumps)
edit:
@Satur9
in terms of energy density lithium is and will be the best.
Thats one big disadvantage for iron salt, the weight/size and density. I think thats the reason why they want to use it for home storage and not for cars.
You gotta be careful listening to media… that image of a pump on the fingertip… yeah that’s just a tiny component inside the actual device. Here’s the actual device.
A far cry from a fingertip sized thing.
TL;DR - the media is the absolute worst place to get your news from.
Let me know if you have any questions with this.
Of course it was ONLY the pump on the picture, nothing else.
But i wonder, if you would really need a pump for a tiny Iron salt battery. Voltstorage uses a pump, because they have containers with several hundred liters liquid in it which have to be brought in contact with the cell. On the other side WE would need less than a drop for a battery. But it is difficult as a layman to make such statements
I recommend you find out the capacity (maybe in Amp-hours) of those several hundred liter batteries, and then divide that by 10,000 (or whatever the dimensional difference is between them and an implant). See if there’s even a few nAh available to work with. Then we have to plan how to manufacture those ourselves, because they’re outside of the normal scope of the product. Then let’s do some testing. See how far we get.
Then let’s repeat that for every battery chemistry we come across and we should be good.
I made some not very successful research just4fun 
It is really difficult to find any information, but i found out that the Vanadium (not Iron) liquid has a capacity of 31Wh/l.
I just assume that we need two drops of liquid (one for negative and one for positive charging) which makes 0,1ml.
my stupid calculation:
31Wh/1000ml x 0,1ml = 3mWh
This would be three milliwatt hours capacity. 
edit: please dont take me seriously
Do you know what the cell voltage is? If for example it would be 1.5V like an alkaline battery, and we only had the one cell (no series or parallel) it would have 2mAh capacity, which could light a very dim red LED at 1mA for 2 hours
Yes 25V. But this is not comparable, because the voltstorage is so much bigger.
Here is the data sheet, if you are interested.
