Page 16 - PEN Ebook May 2021
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Thermal Management Thermal Management
support more power, thus ensuring proper dis- temperature of neighboring cells. Rising tempera-
sipation and avoiding overheating. “But we have tures increase the possibility of shorting adjacent
some challenges to solve: the biggest thing that cells. "Hydra aims to prevent the temperatures
the consumer world is looking for is the price to of neighboring cells from rising above 100 °C and
be very cost effective, and high thermal conduc- thus prevent thermal runaway," said Michael Mo.
tivity performance” said Michael Mo.
Typically, a thermal runaway is caused by exces-
Figure 2: carbon fiber material (Source: Kulr) Michael Mo explained that the FTI solutions family sive current or a high ambient temperature and is
specifically includes Alcor and Mizar FTI materials. developped through several stages: starting at a
The first precaution to be taken is to adopt and Carbon fiber can dissipate heat while reducing He added: “The ALCOR has a density of < 0.7 g/ temperature of about 90-100 °C, the heat gener-
implement a strategy to disperse the heat of the size, weight, and manufacturing complexity. Kulr cm^3, and very low contact pressure to achieve ated causes organic solvents to rupture, resulting
electrical and electronic circuits. The heat trans- has developed a proprietary manufacturing tech- low thermal impedance. The MIZAR FTI increas- in the release of gas and increasing the pressure
fer efficiency of the heat sinks is linked to the nology that organizes 5 to 10-micron carbon fiber es power densities of a board layout and relieves inside the cells. Despite this, the gas does not
thermal resistance between the heat sink and strands onto a base material in a way that looks mechanical stress — resulting in an overall in- ignite due to the lack of oxygen. If, however, the
the ambient space. It measures the ability of a and feels like black velvet. crease in thermal stability and reliability”. temperature continues to rise, exceeding 135 °C,
material to dissipate heat. An ideal heat sink ma- the separator melts and causes a short circuit
terial must have high thermal conductivity, low With the ability to produce 1,800 continuous amps ARA is another solution from Kulr aimed at solv- between the anode and cathode, leading to the
thermal expansion coefficient, low density, and and 2,200 peak amps, the battery in Drako GTE ing thermal management problems in the aero- rupture of the metal oxide cathode at 200 °C and
low cost. is designed to offer megawatt-order power out- space and defense industry as it has a thermal releasing oxygen. This allows the electrolyte and
put and cooling capacity to withstand track-level capability that has experimentally proven effec- hydrogen gas to burn.
The quantity of heat depends on the power and sports performance on various world circuits. tive over a small temperature range. It finds use
on circuit design. The optimal arrangement of the in systems with a large amount of computing As part of battery testing, Kulr developed the
electronic component on a circuit should provide Michael Mo pointed out that producing an elec- power in short time intervals. Michael Mo said LYRA internal short circuit (ISC) trigger cell to
for excellent air circulation and intelligent place- tric supercar needs to involve extreme power they developed a proprietary high thermal con- identify a cell's failure conditions to study the
ment of the parts, taking into consideration the and, by maintaining limited space for heat sinks, ductivity fiber core material to deliver a good failure modes and safety issues that could arise
specifications of the electrical circuit. the thermal interface has its importance. Bringing performance required by space. within battery packs.
the technology used in space environment with
high temperatures allows the electric transport HYDRA is another solution that acts as a heat Interest in battery electric vehicles is stead-
THERMAL sink for lithium-ion batteries and prevents the ily increasing. The real challenge is to make
INTERFACE thermal runaway propagation (TRP): an impor- fast-charging stations available, thus reducing
MATERIALS tant parameter in electric vehicles (figure 3). A battery charging time. This will lead to a signif-
Kulr is using phase change short circuit in a battery pack can cause thermal icant thermal increase in powertrain systems
material with vertically aligned runaway and, therefore, the ignition of fire and resulting in controlled thermal management to
carbon fibre (carbon fiber combustion of materials such as to raise the optimize heat flow.
thermal interface - FTI) for
electronics and lithium-ion For More Information
batteries to serve the world of
electric transportation, ener-
gy storage, battery safety, 5G ▶ Thermal Management Tutorials
infrastructure, cloud comput-
ing, and aerospace and defense ▶ Kulr Technology
applications (figure 2). Figure 3: Example Performance of the HYDRA TRS (Source: Kulr)
16 MAY 2021 | www.powerelectronicsnews.com MAY 2021 | www.powerelectronicsnews.com 17
