The Internet was abuzz for a bit today, when Engaget reported
that a lithium-ion battery was in development, that could store 20
times as much energy as existing batteries, with lower cost.
But then it was clarified
that battereis could deliver 20 times more power.
Apparently, the original article is behind a pay wall, so bloggers are
still wondering what the real story is. Other reports say
report said Hitachi Maxell and a number of universities and
firms in Japan have created a design for a Lithium Ion battery that
will last 20 times longer than current units.
new cell has a discharge capacity 20 times larger than that
of current Li-ion batteries, which means it’s more than capable of
driving a car engine on its own.
So what is the difference, and why does it matter?
There is a difference between energy and power. Energy is the
capacity to do work, whereas power refers to the ability to do a
certain amount of work in a certain amount of time.
Both abilities are important. The ideal battery would store a
lot of energy, and would be able to deliver that
energy at whatever rate is desired. Having a lot of energy
does not do you much good, if you cannot get it to move where you want
it to go at a high enough rate.
Many applications call for a battery to have the ability to delivery a
surge of energy, such as when starting a motor. Therefore,
having a higher power rating is a good thing. But when it
could to running time — that is, how long a device can be operated —
it is the storage capacity that is important.
So, we will have to wait for more detailed information, to see exactly
what this advance will mean in practical terms. It may be
that the lower cost of the new battery will be the more important
advantage. The new batteries will use manganese instead of
cobalt. Manganese is much cheaper. It costs about
$1.70 per 100 grams, while cobalt costs about $21 per 100 grams. (source)
The cost of battery storage capacity is an important component of the
cost of electric and hybrid cars, and many other things.
Reducing the cost of energy storage does not help, directly,
with the cost of the energy itself, or with the problem of energy
shortages, it can help be reducing the cost of solar and wind power
installations that depend upon batteries.