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Moisture Control in Lithium Battery Rooms Dehumidification Application
The choice for
desiccant dehumidification
®
® Reg. TM Bry-Air (Asia) Pvt. Ltd.
O
ver the years, the
manufacturing of lithium
batteries has gone from
relatively small sample batches to
large, mass production operations.
These high energy batteries are
used in a wide range of applications.
The most important single factor
governing the manufacture of lithium
batteries is the fact that they must
be produced in a very low humidity
environment. In the early years,
moisture free (inert gas) glove boxes
were used to produce the batteries
in small quantities.
However, as the demand for
batteries grew, so did the demand
for larger capacity production. At
the same time there were significant
developments in the production
of low humidity dehumidification
equipment. This equipment allowed
for up scaling of the production
process and substantially increased
the production of lithium batteries.
The reason that it is essential to
maintain a low humidity environment
in the production of lithium batteries
is because lithium reacts with water
(vapor) to form lithium hydroxide,
hydrogen and heat. Water vapor
acts as a catalyst, thus the rate
at which these reactions occur
depends upon both the moisture
level in the atmosphere and the time
that the lithium metal is exposed to
that moisture. The more exposure,
the poorer the quality, performance,
and shelf life of the batteries.
A Bry-Air desiccant dehumidifier is
the most efficient and economical
means of providing the very dry
air required for lithium battery
production. The system is specially
designed to control moisture levels
in lithium processing areas at -20°
to -40° F dew point. This condition
represents a moisture content of
less than two grains of water vapor
per pound of dry air.
In designing the system, there are
two key variables which must be
established. The first of these is the
moisture load in the space. This
load is generally made up of the
following:
A. Moisture ingress due to
Photo Courtesy of MCT Direct Photos
M
oisture
C
ontrol

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ithiuM
B
attery

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ooMs
Bry-Air environmental control
systems allow for consistent
control to efficiently by prevent the
effects of humidity on products.
Photo Courtesy of MCT Direct Photos permeation i.e. the vapor
pressure differential between
ambient (surrounding) and the
space to be conditioned.
B. A major contribution to
moisture load is the workers in
the room. Typically an average
person will release 1,500 to
2,000 grains per hour into the
conditioned space through
breathing and perspiration.
The second critical variable to be
defined is the control of the moisture
level in the space. The sizing of
the equipment and thus, the cost,
not only depends on the amount of
moisture to be removed, but also
on how dry the air is to begin with.
The larger the latent load inside the
space, the more CFM it will require
to reach the desired conditions. It
has been clearly established that the
drier the air the better the product
quality. Generally the desired
moisture level varies from -40°F
to-15°F.
Apart from designing an energy
efficient and reliable moisture
control system, great care must
be taken when considering the
construction of the room. The single
most important characteristic of the
construction is that it must be vapor
tight and access must be controlled
through an air lock vestibule.
While control of moisture levels
below -20°F dewpoint is not an
altogether simple problem, it is
certainly well within the range of
existing technology. The low level
moisture control system has become
an essential production tool for other
electro-chemical technologies, as
well as lithium battery systems.
Sodium based batteries and sealed
lead acid batteries can also benefit
from very dry atmospheres during
the production process. In addition,
some types of fuel cells benefit
when moisture is absent during the
assembly operations.
Bry-Air dehumidifiers are working
in many lithium production facilities
around the world, resulting in
millions of dollars saved for our
customers.
Bry-Air, Inc. - 10793 St. Rt. 37 W. Sunbury, Ohio 43074 - P: 740.965.2974 - F: 740.965.5470 - E: bryair1@bry-air.com
For more information on Bry-Airs products and services please visit
www.bry-air.com