Battery Technology - May 2021 - 20

Nanostructured Alloy for Battery Anodes
The alloy could influence the way energy storage devices are designed and manufactured.

Oregon State University, Corvallis

esearchers have developed a battery
anode based on a new nanostructured alloy. The zinc- and manganesebased alloy further opens the door to replacing solvents commonly used in battery
electrolytes with something much safer,
less expensive, and abundant: seawater.
A battery stores power in the form of
chemical energy and through reactions,
converts it to the electrical energy needed to power vehicles, cellphones, laptops,
and many other devices and machines. A
battery consists of two terminals - the
anode and cathode, typically made of different materials - as well as a separator
and electrolyte, a chemical medium that
allows for the flow of electrical charge.
In a lithium-ion battery, as its name
suggests, a charge is carried via lithium
ions as they move through the electrolyte
from the anode to the cathode during discharge and back again during recharging.
Electrolytes in lithium-ion batteries are
commonly dissolved in organic solvents
that are flammable and often decompose
at high operation voltages. Thus, there are
safety concerns with lithium dendrite
growth at the electrode-electrolyte interface that can cause a short between the
electrodes. Dendrites resemble tiny trees
growing inside a lithium-ion battery and
can pierce the separator like thistles
growing through cracks in a driveway. The
result is unwanted and sometimes unsafe
chemical reactions.
Aqueous batteries are a promising
alternative for safe and scalable energy
storage. Aqueous electrolytes are cost-

MnO2

Zn-M

Seawater electrolyte
The seawater battery.

competitive, environmentally benign, capable of fast charging and high power
densities, and highly tolerant of mishandling. Their large-scale use, however, has
been hindered by a limited output voltage and low energy density (batteries
with a higher energy density can store
larger amounts of energy, while batteries
with a higher power density can release
large amounts of energy more quickly).
The new anode is made up of a threedimensional " zinc-M alloy " as the battery
anode (M refers to manganese and other
metals). The use of the alloy with its special nanostructure not only suppresses
dendrite formation by controlling the
surface reaction thermodynamics and the

reaction kinetics, but also demonstrates
super-high stability over thousands of cycles under harsh electrochemical conditions. The use of zinc can transfer twice
as many charges as lithium, thus improving the energy density of the battery.
The team used X-ray absorption spectroscopy and imaging to track the atomic
and chemical changes of the anode in different operation stages, which confirmed
how the 3D alloy was functioning in the
battery. The concept could influence the
design of high-performance alloy anodes
for aqueous and non-aqueous batteries.
" ! ! ! ! !
"
! !

Cobalt-Free Cathodes for Lithium-Ion Batteries
The cathodes could enhance energy density of next-generation Li-ion batteries.

Oak Ridge National Laboratory, Oak Ridge, Tennessee

esearchers have developed a new
family of cathodes with the potential to replace the costly cobaltbased cathodes typically found in today's
lithium-ion batteries that power electric
vehicles and consumer electronics.

The new class of nickel-, iron-, and
aluminum (NFA)-based cathode is a
derivative of lithium nickelate and can
be used to make the positive electrode
of a lithium-ion battery. These novel
cathodes are designed to be fast-charg-

ing, energy-dense, cost-effective, and
longer-lasting.
With the rise in the production of
portable electronics and electric vehicles
throughout the world, lithium-ion batteries are in high demand. Cobalt is a metal
Battery Technology, May 2021

Cov

ToC

http://www.abpi.net/ntbpdfclicks/l.php?202105TBNAV

Battery Technology - May 2021

Table of Contents for the Digital Edition of Battery Technology - May 2021