MINING IN FOCUS
T
he development of next-generation
rechargeable batteries that store more
energy and last longer has been stifled by
an electrochemical challenge. Australian
engineering company, Cornell engineers, has come
up with a simple but clever solution to the problem.
Lithium-ion batteries, like those used in cellphones
and electric vehicles, are limited in their electric-charge
capacity because of their graphite anodes. Researchers
have sought anodes made from alkali metals such as
lithium and sodium because they allow for greater
capacity, but alkali metals are highly reactive with
traditional battery electrolytes. This can lead to the
formation of dendrites – pointy metallic structures that
make the battery susceptible to a shorter lifetime and
potentially dangerous short-circuiting.
Tin as an interface
A team of engineers working in the lab of Lynden
Archer, professor of chemical and biomolecular
engineering, and director of the Cornell
Energy Systems Institute, has
demonstrated a cost-effective
way to stabilise lithium and
sodium anodes using tin
as a protective interface
between the anode and
the battery’s electrolytes.
"Lots of effort has been
devoted to developing sodium-
ion batteries because sodium is
cheaper than lithium.
The research is detailed
in a paper titled,
‘Fast ion transport at
solid-solid interfaces
in hybrid battery
anodes’, published
in Nature Energy in
March this year. By
dropping tin into a
battery’s carbonate-based
electrolyte, the research
team found that an artificial
interface instantly forms on
the alkali-metal anode, creating a
nanometer-thick barrier that protects
the anode like a shield, while keeping it
electrochemically active.
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African Mining October 2019
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