Battery technology

[nobby-w]

https://www.army.mil/article/221700/

Claimed capacity figures equate to approx. 1.6kj/g energy density. Compare to TNT at approximately 4.2kj/g. 40g (approximately the weight per round of a 7.62mm bullet including magazine) is about 65kj. Some quick and dirty maths suggests that this could vapourise 1 mol of water and expand it to about 0.05m³, which is a pretty decent steam explosion.

Note that assumes a 100% conversion efficiency in a hypothetical energy weapon. However, it does suggest that this energy density is enough to power a man-portable energy weapon if such a technology was developed.

 

[mike wightman]

Petrol/gasoline has ten times the energy density of TNT at 46.4 kj/g...

batteries have a very long way to go before they can offer an energy storage capacity that comes anywhere near the energy storage of a chemical fuel.

Liquid hydrogen 141.9 kj/g - there is a reason it is used as rocket fuel

 

[Timerover51]

https://www.army.mil/article/221700/

Claimed capacity figures equate to approx. 1.6kj/g energy density. Compare to TNT at approximately 4.2kj/g. 40g (approximately the weight per round of a 7.62mm bullet including magazine) is about 65kj. Some quick and dirty maths suggests that this could vapourise 1 mol of water and expand it to about 0.05m³, which is a pretty decent steam explosion.

Note that assumes a 100% conversion efficiency in a hypothetical energy weapon. However, it does suggest that this energy density is enough to power a man-portable energy weapon if such a technology was developed.

It sounds like a paper written to make sure that they keep their funding. Beyond that, they have one very long way to go. Lithium is still not the safest metal to use in a battery, otherwise you would not see the Postal Service refuse to ship them.

 

[SpaceBadger]

When you get the =really= energy-dense power cells, then you get the oft-mentioned SF trope of secret agents and special forces types knowing how to short-circuit them for improvised grenades! :CoW:

 

[coliver988]

When you get the =really= energy-dense power cells, then you get the oft-mentioned SF trope of secret agents and special forces types knowing how to short-circuit them for improvised grenades! :CoW:

See: Star Trek communicators on overload

 

[mike wightman]

Or a few phasers can power a shuttlecraft to orbit...

 

[nobby-w]

Petrol/gasoline has ten times the energy density of TNT at 46.4 kj/g...

batteries have a very long way to go before they can offer an energy storage capacity that comes anywhere near the energy storage of a chemical fuel.

Liquid hydrogen 141.9 kj/g - there is a reason it is used as rocket fuel

Of course if you don't have to carry your oxidiser around with you then you get much more energy per kg. The article is not discussing an air-breathing fuel cell technology so I really shouldn't have to spell this sort of thing out.

By comparison a mobile phone extender pack like the one I had has 6x18650 cells, weighing about 45g each with a capacity of about 250kj in total. This comes to about 1kj/g or about 2/3 of the density claimed for the technology in the article. That's the state of the art available off the shelf today.

 

[Timerover51]

.....

By comparison a mobile phone extender pack like the one I had has 6x18650 cells, weighing about 45g each with a capacity of about 250kj in total. This comes to about 1kj/g or about 2/3 of the density claimed for the technology in the article. That's the state of the art available off the shelf today.

Does it work? I have bought my wife two. One simply never worked, while one did. You could say that I have a somewhat jaundiced view of them.

 

[nobby-w]

Does it work? I have bought my wife two. One simply never worked, while one did. You could say that I have a somewhat jaundiced view of them.

As with most consumer electronics, quality varies. The one I had seemed to work fine.