NEWS & TECHNOLOGY BATTERIES
Solid state battery prototype cell extends EV range to 800km
RBy Nick Flaherty esearchers from the Samsung Advanced Institute of
Technology (SAIT) and the Samsung R&D Institute Japan
(SRJ) have shown a prototype solid state battery in a
pouch cell with an energy density of
900Wh/l to give an electric vehicle
(EV) a range of 800 km. A solid state
battery with a solid electrolyte has a
greater energy density than current
liquid versions, which opens the door
for larger capacities, and is safer.
However, the lithium metal anode
used in a solid state battery can still
trigger the growth of dendrites which
can lead to short circuits, overheating
and fires.
So the team at Samsung used a silver-carbon (Ag-C) composite
layer as the anode in a prototype pouch cell to yield a
larger capacity, a longer cycle life and enhanced safety. The use
of a pouch cell means that the technology can be integrated
into existing production lines. Samsung SDI already produces
pouch cells for battery packs for BMW and turned a TV factory
in Hungary into a battery gigafactory to meet demand for
electric vehicles. The Ag-C layer is 5μm and allowed the team
to reduce anode thickness, giving the higher energy density up
to 900Wh/L. It also enabled them to
make their prototype approximately
50 percent smaller by volume than
a conventional lithium-ion battery.
The prototype pouch cell that the
team developed would enable an
EV to travel up to 800km on a single
charge, and features a cycle life of
over 1,000 charges.
“The product of this study could
be a seed technology for safer, highperformance
batteries of the future.
Going forward, we will continue to develop and refine all-solidstate
battery materials and manufacturing technologies to help
take EV battery innovation to the next level,” said Dongmin Im,
Master at SAIT’s Next Generation Battery Lab and the leader of
the project, above right with Yuichi Aihara, Principal Engineer
from SRJ (left) and Yong-Gun Lee, Principal Researcher.
Immersion of electric vehicle batteries:
the best way to keep cool?
By Julien Happich
The electric vehicle market is growing rapidly, and with it
the demand for fast charging, increased energy density
and improved safety. Something that all these areas have
in common is heat. Charging a battery quickly generates a lot of
heat, with the extra energy capacity
of modern and upcoming
electric vehicle batteries,
extracting this heat becomes
more challenging. If this heat is
not distributed effectively, not
only is the performance and
lifetime of the battery greatly
reduced, but thermal runaway
and vehicle fires are a potential
hazard. Immersion cooling is
an emerging potential alternative
to traditional battery
cooling methods and is just
one of the topics covered in
the Thermal Management for Electric Vehicles 2020-2030 report
from IDTechEx.
While most major OEMs in the passenger car market are
utilising air or water-glycol cooling methods, some suppliers are
turning to new methods to meet the increasing thermal demand
on vehicle batteries. This is especially true when considering
more specialised markets such as electric construction and mining
vehicles, in this scenario extremely intense battery discharge
is required and hence a serious amount of heat is generated.
Immersion cooling is one of these emerging technologies for battery
thermal management and has been previously demonstrated
in electronics for data centres, high-performance computing and
grid power systems, but is
now seeing an opportunity in
the electric vehicle market.
As the name suggests,
immersion cooling involves
submerging the battery cells
in a liquid coolant, in doing
so superior thermal contact
and homogeneity can be
achieved. Additionally, the
flame-retardant nature of the
fluids acts as a safety feature,
suppressing thermal runaway
events before they propagate
between cells. A key consideration
here is obviously the choice of coolant fluid used, through
primary research, IDTechEx benchmark the current fluid options,
including those from 3M, Solvay, M&I Materials and Engineered
Fluids. These fluids are all dielectrics but vary in their properties
with factors such as weight, thermal conductivity, environmental
considerations and cost, being extremely important.
XING Mobility are a company specialising in the more niche
electric vehicle markets with their modular immersion-cooled
battery packs utilising 3M’s Novec fluid. In another niche market,
Rimac Automobili have opted for Solvay’s Galden fluid for their
electric hypercars. Whilst the technology shows promise with
Dr James Edmondson, Technology Analyst at IDTechEx -
www.electricvehiclesresearch.com
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