Battery technologies

[ppppenguin]

The chemistry Nobel has been awared to the pioneers of lithium ion batteries.
https://www.rsc.org/news-events/articles...rize-2019/

There have been remarkably few rechargeable battery technologies that have reached the mainstream. And we still need better ones to power portable electronics and vehicles.

Lead acid. The grand daddy of rechargeables. Tough and dependable. Still used massively.

NiFe. Very tough indeed. Now pretty much obsolete.

Nickel-cadmium. Had a long innings but now largely obsolete. Replaced by...

Nickel-metal hydride. Still widely used. Better than NiCd and no nasty cadmium

Lithium ion. A big step in energy density (both for weight and size). The dominant technology for cars, power tools, portable electronics. Our world would look very different if they didn't exist.

Sodium-sulphur never really made it.


Flow batteries look promising for big fixed installations such  as grid scale storage.  Would be fantastic if they were good enough for vehicles as refuelling would be quick and easy.

[Murphyv310]

One of my relatives Jeffrey!!!!!!!!!!!!

[ppppenguin]

I knew you had a college in the family, now a Nobel laureate

https://en.wikipedia.org/wiki/John_B._Goodenough
https://www.goodenough.ac.uk/

[Murphyv310]

Ha Ha

[Mike Watterson]

Nickel-metal hydride. Still widely used. Better than NiCd and no nasty cadmium

Lithium ion. A big step in energy density (both for weight and size). The dominant technology for cars, power tools, portable electronics. Our world would look very different if they didn't exist.

Actually the main difference on capacity after 200 full cycles on NiMH and Lithium Ion is weight. Not volumetric capacity.
In 1970s the NiCd AA was about 450mAH. Early NiMH AA were 500mAH, slightly over 3,000 mAH is now possible. At larger sizes the volumetric efficiency is higher than AA.
The advantages of LiIon are lower self discharge (irrelevant for a laptop?) and much much lower weight. The disadvantages are higher risk of fire or explosion and complex charging. Obviously the single cell voltage (4.2 V down to 3.7 V) and flat aspect radio is an advantage for things like phones, tablets and ereaders. The shape is handy for stupidly too thin laptops.

I'd disagree with the last point (my emphasis). Our world would look very different if they didn't exist
Certainly the rechargeable Lithium batteries are very good, but development has slowed. Lifetime is poor compared to non-gel Lead Acid or Nickel-anything and NiMH have improved x3 in capacity and down to about 1/4 to 1/10th of self discharge since LiIon replaced NiCd and NiMH in laptops and power tools.
Households and workshops now have many LiIon rechargeable things out of fashion and marketing rather than it making any sense (heavier for same power than mains cord version and less environmentally friendly).

NiMH mobile phones, DECT phones, two way radio, gadgets and power tools arn't much different to equivalent tech Lithium powered versions.

[Kalee20]

This is an interesting thread!

I liked NiCd, they don't mind being ignored for ages (I am using some 'D' size Nicads which were left on the shelf for 15 years. They are working at near full capacity.)

I like lead acid, but obviously they need their care - don't leave discharged. Non-reversible crystal growth of lead sulphate slowly kills them.

LiIon on the other hand, I have read that keeping charged actually shortens their life as the side reactions occur to a greater extent when there is loads of metallic lithium.

I've not had enough experience of NiMH, but again read that they don't exhibit 'memory effect'.

I'd be interested in a 3-way comparison, watt-hours per cc; watt-hours per kg, and watt-hours per £, of the various technologies (the last-generation NiCd, when they would be as good as they were going to get). As the terminal voltages are significantly different, mA-H comparisons are not really that helpful. If anyone can put up a little table, I'd be really grateful!

[ppppenguin]

You asked. Google found.
https://en.wikipedia.org/wiki/Comparison...tery_types
You can click to sort the table on any of the parameters. Lithium-ion is split into several different sub-types. eg: Lithium nickel cobalt aluminum oxide

More words, simpler table:
https://batteryuniversity.com/learn/arch...st_battery

[Kalee20]

Thanks, Jeffrey!

Interesting that Nicad is actually the cheapest in terms of cost-per-cycle, according to BatteryUniversity, and lithium about 7x more expensive!

[BusyBee]

I am not sure about things in absolute terms here but it has been my feeling for some time that modern Lithium batteries are not all they are cracked up to be, In practice I found that the memory effect that plagued Nicad batteries was more an illusion than not as I found extended low rate charging seemed to overcome it. Even when short the cells could be flashed, but that seemed fairly short term. At work we found the NiMh cells could have a fairly short life when stressed. Although they have initial higher capacity I am not sure of the long term (I won't be buying a cordless Dyson as I dread to think of replacement battery cost). It is also interesting to note, these days, that when car batteries fail they seem to just go, not whinging and whining for months giving time to plan replacement. To be honest I fear modern battery capacities as a Lithium battery is like an unexploded bomb. We are now seeing cases of deaths caused (maybe inappropriate use but they ought to be foolproof for expected malpractice). An old lead acid cell could be lethal but it did generally require positive action on the user to perhaps deliberatly drop a spanner on the terminals and it was probably the acid that caused more issues.

Tracy