About the GMET
company is organized by a team of engineers who had been
long time experienced in the fields of Electrochemical,
Precision Mechanical manufacture and Electrical engineering.
Most of engineers had been also producing small size of
prismatic Li-battery cells applied in the commercial devices
such as cellular phones, pad and electric books more than 8
years with more than 100 millions of Li-battery cells
delivery experiences. The type of Li-battery experienced are
Lithium cobalt oxide (LiCoO2) batteries, Lithium polymer
battery and LiFePO4
The R&D engineers have the capability of developing
Electrolyte to meet the cell capacity of customer’s
requirement in certain range. The sources of cathode
material are from two authorized suppliers in Taiwan.
Currently electrical engineers usually connect more than
thousands of cells in the application of Li-Battery. However
if there were one single cell with 60 Ah, the numbers of
cells through series or parallel connection to achieve high
capacity application would be significantly reduced. It also
reduce the electrical resistance when pack those small
capacity cells as a battery by bridge connectors.
With a vision of future high capacity and
safe battery required in the applications of EV, Electric
Bus, Electric motorcycles, storage, and replacement of lead
Acid battery for environmental protection, to develop a
differential design of high capacity cell would be necessary
in the world, the company was established in year 2011.
GMET has set up three divisions in the company for the
The Cell enclosure division
is dedicated to design and development on the enclosure and
connectors for cells. The high capacity Lithium battery
cells must have a safety protection enclosure to assure its
perfect performing on the output of electric power in the
The Cell manufacturing division
has set up an in house production line with capacity of
20,000 kWh annually (400 pieces of 60AH daily). A laser
cutting process has developed to prevent the chips occurred
on the edge of each cathode and anode sheets. The production
capacity can be expanded to meet the requirements of
customers in five months.
The Cell pack division
is dedicated to sourcing BMS or working with customers to
develop BMS on each different requirement of application to
assemble cells as a battery pack in house. It also takes
advantages of developed connectors to pack cells in terms of
low AC impedance and longer stand of cells life.
Objectives of GMET
1.To develop high capacity of Li battery Cell, 3.2V 20 AH
and 3.2V 60AH.
2.To develop effective Relief Vent for the safety of high
capacity of Li-Battery Cell.
3.To develop aluminum enclosure for High capacity of
4.To improve the electrical resistance when cells packed
through series or parallel connections.
of Li-Battery cost per KW is US$500.
Battery Cell Enclosure
The enclosure division is dedicated to the design and
development of variant size of high capacity cell sealed in
an aluminum shell. The key challenge design is to develop
Square Surface Terminal (SST), which provides a
non-interrupt path for electron flow from one tab of
electrode to terminal outside of cell. The SST design
eliminates the screws inside of the terminal. In addition
the bridge connector connecting terminals between two cells
is tightened by indirect screws that reduce the possibility
of loosen between terminals and bridge connectors when
battery is operated in a vibration movement.
In most of the high power applications users usually connect
small capacity of battery cell, like 18650 cylindrical cells
to achieve its applications requirements. It always requires
more than thousands of cells in one application. However if
there were one single cell with 60 Ah, the numbers of cells
to series or parallel connection would be significantly
reduced. It also reduce the electrical resistance when pack
those high capacity cells as a battery by bridge connectors.
The heat would not generate for a battery in high output or
long service if the electrical resistance of bridge
connectors can be effectively controlled in minimum. By this
way the performance of battery can be significantly improved
to achieve the expectations of electrical engineers.
Design of Relief Vent
Vent open can be controlled by
Pressure or by Temperature
The relief vent on the SST is a destructive mechanism which
would discharge Electrolyte when the vapor pressure reach
0.3~0.6 Mpa (0.6 m Pa or 5.9 atm, 87 psi or 6.11 Kg f/㎟)
in an abnormal operation condition. The relief vent on cell
is able to sustain external shock & vibration force from
operation without damage.
The most advance mechanism is Vent Open Controlled by
Temperature at95℃ when battery cell occurs abnormal
There is no relief vent designed to destroy cells by
temperature control in the world. The dangerous of battery
cell is when thermal runaway happens in the cell that is the
chemical reaction temperature at 380℃. It would be much
effective if we can discharge the electrolyte to cool down
the cells at 95 ℃ before it gets runaway temperature 380℃ in
an abnormal cell. The cut off point for abnormal cell at 95℃
is much earlier than the critical temperature 140℃.
The Technical Advantages of GMET
of Electrolyte Chemical Composition development. Li-Fe,
Li-Cobalt Li- Polymer etc,.
of Enclosure design on both of soft and hard shells.
of Process Machinery design.
of Cells Mass Production.
house Cells manufacturing Capacity.
Pack Manufacturing Capability.