Batteries – what are they good for?

Okay, 'energy storage' – but what else are they good for?

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Keith S. Taber

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I was struck by an item on the BBC Radio 4 news headlines at 09.00 this morning (27th Feb. 2023):

"The collapsed battery maker Britishvolt which went into administration last month has been bought by an Australian company.
The new owners will focus initially on batteries for energy storage rather than electric vehicles."

BBC Radio 4 news item

Now on reflection, this was an ambiguous statement. I heard it as

"The new owners will focus initially on batteries for

• energy storage, rather than
• electric vehicles."

Which immediately provoked in my mind the question what batteries might be used for in electric vehicles – if not 'energy storage'?

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Conceptions of energy

Now, this whole area is, metaphorically, a bit of a linguistic minefield as when people say batteries they do not usually distinguish between an individual cell and a battery (of cells). Traditional electrochemical cells we are familiar with have a specific and usually modest e.m.f. – 1.5V or 1.2 V for example. The old 6V and 9V batteries that used to be commonly sold for many purposes (before the switch to most appliances having internal batteries) would be batteries of cells connected in series to work together to provide (1.5V + 1.5V + 1.5V + 1.5V = ) 6V (or whatever). Car batteries were traditionally batteries of lead-acid cells connected together. If each cell has an e.m.f. of 2V, then a dozen connected in series (i.e., the battery) offers 24V.

Moreover, energy is a highly abstract idea, such that even physics teachers do not always agree on how to describe it – the model of energy coming in a number of flavours, 'forms', and processes involving transformations in the form of the energy (e.g., a filament lamp converts electrical energy into heat energy) that many of us learnt (and some of us taught) has come to be seen as misleading and unhelpful by some (it not all) educators. Oh, and if you think I made a mistake there and forget that a lamp produces light energy – not at all. In the 'forms of energy' typology, heat is energy transferred due to a difference in temperature – so that covers all the radiation being emitted by the hot filament.

No wonder, that energy is a common topic for student alternative conceptions, as energy permeates (so to speak) all areas of science, but is a highly abstract notion.

Read about conceptions of energy

An alternative hearing?

Yet, I realised that the statement I had heard was ambiguous and could be parsed differently. It perhaps meant

"The new owners will focus initially on

• batteries for energy storage

rather than

• electric vehicles."

That is, I was putting my imaginary brackets in the wrong place and perhaps the company had previously intended to build complete electric cars and not just the batteries? If so, the news was not

• The new owners will focus initially on batteries (for energy storage rather than electric vehicles).

but rather that

• The new owners will focus initially on (batteries for energy storage) rather than (electric vehicles).

If this was the intention, it might have been better to have assumed listeners would know that batteries were used for 'energy storage', and to have simplified the statement to

"The new owners will focus initially on batteries rather than electric vehicles."

Batteries for under-performing sports cars?

That made more sense, as surely the BBC's news journalists do not think electric batteries in cars are used for something other than 'energy storage'. So, I checked on the BBC news website, where I found

"The company intends to start by focusing on batteries for energy storage and hopes to have those products available by the end of 2025.

It then intends to produce batteries for high-performance sports cars."

https://www.bbc.co.uk/news/business-64754879

So, I did not misinterpret the news item. According to the BBC (and to be fair, they are probably just reporting, albeit uncritically, what they have been told) under its new owners Britishvolt will

• first work on batteries that can be used for energy storage, and
• then shift attention to batteries for sports cars.

My best guess is that "batteries for energy storage" is shorthand for large scale devices for long term storage (that could, for example, be charged by wind generators when it is windy, and then later fed into the National Grid at times of high power demand). The characteristics of these devices would surely be different in detail from batteries used in electric vehicles.

However, I am pretty sure that "batteries for high-performance sports cars" also need to provide 'energy storage' or else those cars are not going to offer the kind of performance Britishvolt and the car manufacturers they will supply are looking for. After all, besides 'energy storage', what else are batteries actually good for?

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