In 2010, Canadians purchased 22,843
tonnes of batteries. Less than a third of those were rechargeable, and many
ended up in landfills. We all use rechargeable batteries in our cell phones and
laptops, in our calculators and our cars, but many of us still buy single-use
batteries for portable devices like flash lights, remote controls, and toys.
About 88% of the total mercury and 50% of the cadmium found in
municipal waste comes from batteries.
Recycling your batteries can help reduce
mining of materials for battery production, as can buying rechargeable
batteries. Furthermore, buying rechargeable
batteries can also save you a lot of money. A pair of rechargeable AA
batteries costs about four times as much as a two single-use AA batteries, but
you can use your rechargeable batteries hundreds of times!
What
is a battery?
Simply put, a battery is a portable
source of energy that produces electricity by chemical reaction. The amount of
electricity a battery produces varies widely depending on the type and amount
of materials used to construct the battery.
How
does it work?
A battery is made up of one or more
“cells” which comprise two different metals (electrodes) connected by wire on
one end, and in contact with an electrolyte solution on the other. One electrode
has an excess of electrons (a negative charge) and one has a deficit of
electrons (a positive charge). The chemical reaction between the metals and the
solution causes electrons to travel from the negative terminal to the positive
terminal, producing electricity.
Common
Batteries
A battery will either be wet-cell, where
the electrolyte solution is liquid (as in a car battery), or dry-cell, where
the electrolyte solution is a paste. Batteries fall into several sub-groups,
based on chemical composition. The
performance and life of the battery will vary by manufacturer, but batteries
with the same basic chemical composition share many characteristics.
Lead-acid batteries are your traditional car batteries. They are also used in
other applications where weight and size are relatively unimportant, like
emergency lighting systems and wheelchairs. Lead-acid batteries actually have a
liquid electrolyte solution, so are heavy and must be treated carefully.
Alkaline batteries are most commonly found in the traditional sizes of AA,
AAA, C, D, etc. These batteries come in both disposable and rechargeable forms,
the disposable kind being the cheapest. The rechargeable version tends to have
a low-discharge rate (producing less power at a time) so is best used in
low-energy devices like clocks.
Nickel-metal
hydride (NiMH) batteries are also available is
traditional sizes (AA, C, D). They are rechargeable and have a high-discharge
rate, so are good for use in electronic devices like digital cameras. They are
now used in hybrid cars instead of lead-acid batteries because of their lighter
weight and smaller size.
Lithium-ion batteries are mostly used in cell phones, laptop, and notebook
computers. They are lightweight and rechargeable, but can also be fragile. Lithium-ion
polymer (LiPo) batteries are pretty much the same, but can be packaged in a
wider variety of sizes and shapes.
Nickel-cadmium (NiCad) batteries have a long shelf life and a high discharge rate,
but low energy density. They are often used in 2-way radios, power tools, and
professional cameras. These batteries are, however, quite toxic and must be disposed of properly. NiMH
batteries are largely replacing NiCad batteries in consumer products.
Button batteries are small, disposable batteries most commonly made using
zinc or lithium. You’ll find them in wristwatches, calculators, and other small
electronic devices.
Recharging
Recharging reverses the chemical
reaction in the battery, allowing the electricity-producing reaction to happen
over and over again. The battery can keep producing electricity until it
eventually wears out.
A rechargeable battery has a limited
number of charge cycles. It is not an exact number, but the following table can
give you a rough guideline of what to expect from different types of batteries:
*These are average numbers and may
vary depending on manufacturers, as well as the use the battery will undergo.
From the purchase of a battery to its
eventual expiration, the life of the battery and amount of use you get can vary
widely depending on the type of battery, storage, and usage. How you use your
batteries can either extend or diminish the life of the battery.
To get the most out of your batteries,
follow a few easy steps:
- Use the right type of battery for the device.
- Turn off devices when they aren’t being used.
- For items that are used infrequently, remove batteries between uses.
- For rechargeable batteries, don’t leave them on the charger once they’ve been fully charged; they lose a percentage of their capacity if left on the charger too long.
- Store unused batteries at or below room temperature.
Recycling
Depending on the composition of the
battery, the recycling process varies. Other batteries are too small and
delicate for such recycling, so batteries like Lithium-ion are shredded and
turned into other products, like industrial lubricants. Other batteries are not
as valuable to reclaim, but still have components that are worth salvaging, and
remaking either into new batteries, or into other products.
The
Recycling Process
First, the batteries are sorted by
chemistry. Each type of battery requires a different process to separate and
reconstitute the individual components.
In the case of lead-acid batteries acid solution, the plastic, lead and other
components are all separated. The lead is melted, purified, and remolded for
use in new batteries. The acid solution is neutralized, filtered, and
reconstituted to use in new battery cells. The plastic is also refurbished and
made into new battery casings.
Lead-acid batteries have been
consistently recycled for decades, thanks to the organization of the auto
industry in reclaiming used batteries. Between 98% and 99% of lead-acid car
batteries are recycled and remade into new batteries.
For other battery types, the components
are also separated, and in some cases remade into new batteries, but can also
be made into other products. Lithium
batteries, for example, are frozen with nitrogen to neutralize the lithium,
before the batteries are crushed and shredded. The lithium is then separated
and rendered non-reactive before being sold to produce lubricating greases. The
cobalt in the battery is also separated and sold for reuse.
Where
can I recycle my batteries?
Many retailers will accept batteries for
recycling that have been purchased in-house, and more and more retailers and
depots now take batteries for recycling.
To find out how and where to recycle
your batteries, check out:
In Canada, the annual recycling rate of
batteries (other than car batteries) was less than 20% as of 2009. The good
news is that Canada has the infrastructure to process and recycle all of the
batteries that Canadians use each year.
Sources: ODEC, Technology & Science, EZE Living, Life of Earth, Tonolli, The Money Track, Raw Materials, ec.gc.ca, Eco Evaluator, Inventors, E How, Battery University, Buy Chargeall, HRSDC, Recupyl, Earth 911
