The lithium-ion (Li-ion) battery has been
thrust into the limelight in recent years.
Driven most recently by the growing
popularity of electric vehicles (EVs), its usage has risen
sharply, pushing up demand for its constituent minerals and
This phenomenon is perhaps best
illustrated by the rocketing price of lithium, the mineral that
lends its name to the battery category, and a market caught off
guard by the sudden growth in demand, with supply struggling to
On the China spot market the price of
lithium rose from $7.7/kg in June 2015 to a peak of $26.8/kg in
June 2016. In the rest of the world, meanwhile, contract prices
for 2017 have doubled from 2016
levels, according to IM’s
Experts now speak of the need for another
full project to come online each year for the next few years in
order to satisfy the growing demand.
The current supply tightness has led some
in industry to ask – why not recycle lithium from
Li-ion batteries and reuse it?
The answer is simple. For now at least,
the quantities and processes involved make this
The core of the issue is the relatively
small proportion of the cost of the battery which lithium makes
"The price of lithium would have to go way
up before it seriously impacted the cost of the battery," Linda
Gaines, transportation system analyst at the Argonne National
Laboratory in Illinois, US told IM.
While materials make up the largest part
of the cost of the battery and the cathode accounts for the
majority of materials cost, the part of this attributable to
lithium is relatively small.
The cost of other cathode materials, such
as cobalt, is more of a worry to cathode producers than the
cost of lithium. For cobalt in particular, cathode makers are
seeking alternative raw material options driven partly by its
cost, said Gaines.
But this is not the case for lithium.
On top of this, primary production of
lithium is not energy intensive, Gaines explained, particularly
for lithium production from brines, where solar evaporation is
used to extract the mineral from salt flats.
"[The process] is not energy intensive and
it’s not expensive. Lithium carbonate is not an
expensive material," she said.
As a result, the expense of separating out
a small quantity of lithium from recycled batteries, while
possible in some situations, is not justified by the value of
what can be gained.
"It may not pay to get lithium back," said
There are two methods of recycling Li-ion
batteries – pyrometallurgical and hydrometallurgical
processing. The former involves putting batteries in a furnace
and treating them thermally, while the latter involves treating
them chemically to separate the materials.
The only large scale Li-ion recycling
facility currently in operation is Umicore’s plant
in Hoboken, Belgium, where the company employs both methods to
break down batteries.
According to Umicore, it uses a form of
pyrometallurgy, employing its own ultra-high temperature (UHT)
technology, to separate batteries into three parts –
an alloy (containing the valuable metals – cobalt,
nickel and copper); a slag fraction, which can be used in the
construction industry; and clean air.
The alloy can be further broken down using
hydrometallurgy, while the slag element has the potential for
Full hydrometallurgical processing
involves chopping up the battery to recover aluminium and
copper foils, as well as a black mass of active materials,
before screening out big pieces of metal – the foils
that had held the anode and cathode.
At this point, lithium ions dissolve out
into a solution and metal oxides and carbon (graphite) are
The graphite is usually then burned off in
the pyrometallurgical recovery of the metal oxides. It is in
theory possible to recover the graphite, if instead the metals
were recovered as salts, this is not currently a method
employed by any company. And, as IM explained
in a recent feature, graphite
is not in short supply at present.
While lithium extraction from Li-ion
remains problematic, it is possible to extract it from primary
One company that does this is Retriev
Technologies, which operates a facility in Ohio, US.
Retriev makes use of a proprietary
cryogenic process to treat the highly reactive batteries,
before crushing them into metal solids and a "lithium-enriched
solution". The lithium sulphate in the solution is then
converted to lithium carbonate.
Cost makes this process unfeasible for
"The filtrate solution from processing
primary lithium batteries can be used to create lithium
carbonate, but the recyclers don’t generally do
this with lithium-ion because it’s just too
expensive. There’s less lithium per battery," said
The world is becoming more reliant on the
mineral to power the growing use of Li-ion technology.
But given that the recent lithium price
spike did not justify recycling of Li-ion, unless technology
makes the cost of the process significantly lower, the process
is unlikely to become large scale in the near future.