15 May 2014
Details
The PbC® battery is a hybrid device
that uses the standard lead acid battery positive electrode
and a supercapacitor negative electrode
that is made of activated carbon.
The specific type of activated carbon
we use has an extremely high surface area (1500 m2/g)
and has been specifically formulated by Axion
for use in electrochemical applications.
During charge and discharge,
the positive electrode undergoes the same chemical reaction
that occurs in a conventional lead acid battery,
i.e. lead dioxide reacts with acid and sulphate ions
to form lead sulphate and water.
The main difference in the PbC® battery is
the replacement of the lead negative electrode
with an activated carbon electrode
that does not undergo a chemical reaction at all.
Instead, the very high surface area
activated carbon electrode stores the protons (H+)
from the acid in a layer on the surface of the electrode.
This new negative half reaction can be written as the following:
- Negative Electrode in the PbC® battery technology
nC6x-(H+)x D nC6(x-2)-.(H+)x-2 + 2H+ + 2e- (discharged)
In conventional lead acid batteries
the concentration of acid changes from
being very concentrated in the charged state
to somewhat dilute in the discharged state
as the acid is converted to water.
In contrast, the PbC® battery
stores H+ in the negative electrode
in the fully charges state
which move to the positive electrode during discharge
where they are neutralized to form water.
The result is reduced acid concentration
swings from the charged to discharged state
which reduces grid corrosion
on the positive electrode and
leads to longer life of the positive electrode.
UTILITY GRID CONNECTED POWER
Grid connected power
refers to
short-term storage for utility-scale energy producers.
Axion's principal focus is
short-term storage for renewable energy
such as wind and solar power.
The rapid recharge and deep discharge capacity
of our PbC® b
intermittent power sources like wind and solar.
When coupled with our ability to deliver longer cycle lives
with minimal maintenance, we believe
grid connected systems based on our PbC® technology
will be able to offer a greater total number of
useful cycles lives.
If battery cost per charge/discharge cycle
is low enough, peak shaving and grid buffering
for traditional utilities may also be cost effective.
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