What is Nanowire Battery, How it is different from lithium ion battery, Construction of Nanowire Battery, Comparison with other Energy Storage Systems, Advantages, Disadvantages, Application, Future Scope

1. Nanowire
Battery
Dharnesh K
CB.EN.U4ELC19013

2. Introduction
Lithium-ion batteries are common in consumer
electronics. They are one of the most popular types of
rechargeable batteries for portable electronics, with a
high energy density, no memory effect, and only a slow
loss of charge when not in use.
Thus with such wide applications, it was felt the need for
the lithium ion battery to have a higher capacity and
longer cycle life and hence the lithium battery with
silicon nanowire was developed .
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3. Lithium-Ion Battery Development
In the 1970's, Lithium metal was
used but its instability rendered it
unsafe and impractical.
The Lithium-Ion battery has a
slightly lower energy density than
Lithium metal, but is much safer.
Introduced by Sony in 1991.
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4. Lithium-Ion Battery
A lithium -ion battery is a member of a family
of rechargeable battery types in which lithium ions
move from the negative electrode to the positive
electrode during discharge and back when
charging.
Separator is used to prevent physical contact
between the anode and cathode, while facilitating
ion transport in the cell
Anode- Graphite
Cathode- Lithium Cobalt Oxide
Electrolyte- LiPF6
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5. Charging and Discharge cycle
➢ During charging,an external electrical
power source applies a positive voltage
across the cathode and anode, electrons
starts to flow through the external circuit
➢ The lithium ions then migrate from the
positive to the negative electrode, where
they become embedded in the porous
electrode
➢ During discharge, lithium ions Li+ carry
the current from the negative to the
positive electrode,through the non-
aqueous electrolyte
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6. Need for Silicon Anodes
The electrical storage capacity of a Li-ion
battery is limited by how much lithium can be
held in the battery's anode, which is typically
made of carbon
Silicon is an attractive anode material for
lithium batteries because it has the highest
known theoretical charge capacity (4,200
mAh) .
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7. Why Silicon Anodes are not used
But the only disadvantage is silicon
placed in a battery swells during
charging, then shrinks during use and this
expand/shrink cycle typically causes the
silicon to pulverize, degrading the
performance of the battery.
The solution to this problem is
Nanowires
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'structured' silicon in the form of micron-
dimension pillars

8. Nanowire
► Nanowires are microscopic wires that have a width
measured in nanometers.
► 1D structures:
Diameter: 1-100 nanometers (10-9 m)
Length: microns (10-6 m)
Typical aspect ratios of 1000 or more.
► Crystal structures close to that of the bulk material
► The only difference is in terms of its size.
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9. Nanowire Battery
► In 2007 the new technology was developed at Stanford University by a team led
by Dr. Yi Cui.
► The Nanowire battery is a lithium ion battery, which consists of a stainless steel
anode that is covered in silicon nanowires.
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10. Nanowire Battery
► A nanowire battery uses nanowires to
increase the surface area of its electrodes.
► The lithium is stored in a forest of tiny silicon
nanowires, each with a diameter one-
thousandth the thickness of a sheet of paper.
► The nanowires were grown on a stainless
steel substrate providing an excellent electrical
connection.
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11. Synthesis of Nanowire Battery using
VLS method
The silicon nanowire synthesis using VLS method:
(i) Gold nanoparticle deposition and thermal annealing
(ii) Reduction of silane gas to silicon vapor.
(iii) Diffusion of silicon vapor via gold nanoparticles.
(iv) Formation of SiNWs via super-saturation with silicon.
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12. Special Characteristics of Nanowire
Batteries
►Anode thickness is reduced to half of a graphite
electrode thickness
►Nanowire batteries are lighter, safer, and have more
energy density
►Nanowires tolerate volume expansion and are rooted to
the substrate
►Nanowires have micro and macro porosity that
accommodate swell
►Nanowires improve Solid-Electrolyte-Interphase & cycle
life
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13. Technological Comparisons
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Technology Power density Energy density Lifetime Efficiency
Fuel cells Low/moderate High Low/moderate Moderate
Supercapacitors Very High Low High High
Li-ion w/r graphite Moderate Moderate Moderate High
Li-ion w/r SiNW’s Moderate Very High High High

14. Advantages
►Eco friendly.
►High energy density(300-450 Wh/kg)
►Protects from explosions.
►Light in weight.
►Smaller in size
►High storage capacity(4200mAh).
►Fast charging capability (1-80% in 6 minutes)
►Nanowire technology enables the highest ratio of
energy to power
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15. Disadvantages
▶ High temperatures of 600 to 900 degrees celsius are needed to perform the
synthesis of Silicon nanowire
▶ Expensive
▶ Only the anodes are manufactured as nanowire structure
▶ Still needs more research in nanotechnology
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16. Why Are Nanowires Batteries Not
Being Implemented?
►Nanowire are not being heavily manufactured because they are still in the
development stage and are only produced in the laboratory.
► Until production has been streamlined, made easier and faster, they will not be
heavily manufactured for commercial purposes.
► But the advantage is that this is the only part of the battery that is different from
conventional lithium batteries, so the rest can be produced using existing
manufacturing methods, components and processes.
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17. Future scope
▶ In future,ordinary Li-ion batteries will be replaced
by Nanowire based batteries completely
►By invention of some new mechanism and
technology, we can get Nanowire batteries have more
than 10 times the ordinary battery.
►Amprius technologies is one of the leading company
in the research of Nanowires technology.
►Recently they are in talks with Tesla to implement
the nanowire batteries in Tesla electric cars 17

18. Applications
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►Hybrid and Electric vehicle (EV) applications
►To power laptops, iPods, video cameras, cell
phones, and countless other devices.
►Used in Bio-Medical applications
►useful in Portable Power Packs

19. Applications
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Silicon lithium-ion batteries are
game-changers. Having the highest energy
density in the industry, these batteries can
substantially improve the performance of
electric vehicles, aircraft, drones, and
wearables.

20. References
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►https://amprius.com/technology
►http://nanowirebattery.blogspot.com/2008/11/disadvantages-of-nanowire-
battery.html
►C. K. Chan, R. Huggins, Y. Cui and co-workers Nature Nanotechnology 3,31 (2008)
►Nanowire Batteries for Next Generation Electronics Candace K. Chan, Stephen T.
Connor, Yuan Yang, Ching-Mei Hsu, Robert A. Huggins, and Yi Cui
►Porous Doped Silicon Nanowires for Lithium Ion Battery Anode with Long Cycle
Life Mingyuan Ge, Jiepeng Rong, Xin Fang, and Chongwu Zhou

21. Thanks!
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