Short charge life of a normal mobile phone battery has been a universal problem. Even though Smartphones are getting more and more powerful, the battery life still remains a huge bottleneck for their growth. Even the most superior smartphones today struggle to offer full day battery life with moderate usage.
Its not the battery alone, but the charging times is also an issue – Generally, a normal mobile phone takes atleast a couple of hours to get to a full charge. So, it is very difficult to completely charge your battery when on the move.
But looks like a 18 year old Indian American girl Eesha Khare has found a problem to the solution with her invention. She has come up with a small device that can be fitted inside mobile phone batteries and could them in about 20 to 30 seconds.
This invention won her Young Scientist Award by the Intel Foundation, which also carried a prize money of USD 50,000.
According to her, the tiny device has has a life of 10,000 recharge cycles as compared to 1000 cycles of traditional rechargeable batteries.
Here is a video of Eesha Khare at the Young Scientist Awards function and her talking about her invention.
The core of Eesha’s discovery is super capacitors – These are storage devices that can be charged or discharged a hundred or a thousand times faster than regular batteries. However, the problem is that their fabrication is both costly and cumbersome.
Here is an excerpt from Eesha’s whitepaper that talks about how she made this 20 second charger.
[box type=”info” ]To improve supercapacitor energy density, I designed, synthesized, and characterized a novel core-shell nanorod electrode with hydrogenated TiO2 (H-TiO2) core and polyaniline shell. H-TiO2 acts as the double layer electrostatic core. Good conductivity of H-TiO2 combined with the high pseudocapacitance of polyaniline results in significantly higher overall capacitance and energy density while retaining good power density and cycle life. This new electrode was fabricated into a flexible solid-state device to light an LED to test it in a practical application.[/box]
Earlier last year, another UCLA researcher had made a DVD based super capacitor that created over a week’s batter on single hour of recharge. What the researchers did was used graphite oxide to coat a plastic layer on a disk and used the laser in the DVD-burner to create super micro-capacitors. You can read more about it here.
Overall, it looks like the next big thing in mobile phones is going to be the battery life. Imagine how great would it be to have a week long battery on your smartphone, or a battery that could be re-charged in 20 seconds.
I hope these inventions soon start becoming commercially viable and become available on today’s devices, which desperately need them!
Design and Synthesis of Hydrogenated TiO2-Polyaniline Nanorods for
Flexible High-Performance Supercapacitors – paper published by her mentor a year prior
“It demonstrated high
capacitance of 203.3 mF/cm2 (238.5 F/g) compared to the next best alternative supercapacitor in previous
research of 80 F/g, due to the design of the core-shell structure. This resulted in excellent energy density
of 20.1 Wh/kg, comparable to batteries, while maintaining a high power density of 20540 W/kg. It also
demonstrated a much higher cycle life compared to batteries, with a low 32.5% capacitance loss over
10,000 cycles at a high scan rate of 200 mV/s.”
A typical lithium-ion battery can store 150 watt-hours of electricity in 1 kilogram of battery. A NiMH (nickel-metal hydride) battery pack can store perhaps 100 watt-hours per kilogram, although 60 to 70 watt-hours might be more typical. A lead-acid battery can store only 25 watt-hours per kilogram.
http://gigaom.com/2011/07/12/how-ultracapacitors-work-and-why-they-fall-short/
A typical 20-microfarad capacitor would be able to handle as much as 300 volts, while an ultracap would be rated at only 2.7 volts. At a higher voltage, the electrolyte starts to break down.
Because an ultracapacitor stores energy in an electric field, rather than in a chemical reaction, allows ultracapacitors to charge and discharge much faster than batteries ( more than 1,000,000 cycles vs. hundreds for batteries). Because capacitors don’t suffer the wear and tear caused by chemical reactions, they can also last much longer(>10 yrs vs 3-5 yrs for Liion batteries).
It would be technically possible, for example, to use ultracaps instead of lithium-ion batteries in cell phones, with some serious benefits: You would never have to replace the ultracapacitor, said Schindall, professor in MIT’s LEES and the phone would recharge very quickly. But the phone wouldn’t stay charged for very long at all with today’s ultracapacitors—perhaps as little as 90 minutes, or five hours max, Schindall said.
Ultracapacitors are very effective, however, at accepting or delivering a sudden surge of energy, and that makes them a good partner for lithium-ion batteries
• Applications: Low supply current during longer times for memory backup in (SRAMs)
• Power electronics that require very short, high current, as in the KERSsystem in Formula 1 cars
• Recovery of braking energy for vehicles
As of 2013 commercially available Lithium-ion supercapacitors offered the highest gravimetric energy density, reaching 15 Wh/kg
. Some examples of new developments(Wikipedia):
• Vertically arranged carbon nanotubes
A supercapacitor with vertically arranged carbon nanotubes as electrodes offer energy density above 60 Wh/kg and a lifetime of 300.000 cycles is under development.[22][65] First discrete capacitors are bargained by FastCap Systems.[166]
• Curved graphene sheets
As of 2010 graphene-based electrodes of experimental supercapacitors offered density of 85.6 Wh/kg at room temperature.[59][60] These electrodes work with single-layers of curved graphene sheets that do not restack face-to-face, forming mesopores that are accessible to and wettable by environmentally friendly ionic electrolytes at a voltage up to 4 V.
A related development reached an energy density of 85 Wh/kg in mid-2011 with a carbon-based electrode.[167][168][169] The energy density values are valid for the weight of the electrodes only, while complete capacitors will have roughly the half of the experimental values.
• Tailored porous carbon
As of 2010 synthesized porous carbon with a continuous three-dimensional network of highly curved, atom-thick walls form primarily 0.6 to 5 nm width pores with a surface area of 3100 m2/g. Electrodes offer an energy density of about 70 Wh/kg. A practical energy density of above 20 Wh/kg for a packaged device is expected.[170]
• Conjugated microporous conductive polymer
As of 2011 a new conductive polymer for pseudocapacitor electrodes was announced – conjugated microporous polymer (CMP). This material is a sub-class of a porous material, related to conductive polymers, that allow a large number of faradaic reactions. An Aza-fused ?-conjugated microporous framework provided an energy density of about 50 Wh/kg and a charge/discharge cycle stability of 10,000 cycles.[171][172]
• Tailored composite electrode
A composite carbon electrode material with a tailored meso-macro pore structure of single-walled carbon nanotubes enabled the composite electrode to retain more electrolyte, ensuring facile ion transport, hence achieving maximum power rating 990 kW/kg.[173]
• Nickel hydroxide composite electrode
As of 2012 an asymmetric supercapacitor with a composite anode deposited nickel hydroxide (Ni(OH)
2) nano-flakes on CNT bundles as pseudocapacitive material, achieving an energy density up to 50.6 Wh/kg.[174]
• Battery-electrode nanohybrid capacitor
Battery developments often force the development of SC composit electrodes. A battery-capacitor hybrid device called “Nanohybrid capacitor”, composed of deposited Li
4Ti
5O
12 (LTO) on carbon nano fibres (CNF) anode and an activated carbon cathode delivered energy density of 40 Wh/l and high power density of 7.5 kW/l the same power density of standard supercapacitors. It survived 10,000 cycles.[76]
• Nickel cobaltite deposited carbon aerogel composite electrode
As of 2012 a new composite carbon aerogel electrode deposited with nickel cobaltite nanocrystals exhibited 1,700 F/g was developed. The success is enabled by using highly conductive mesoporous carbon aerogels as the hosting matrix and an ultrathin NiCo
2O
4 nanostructure on the backbone of the matrix for pseudocapacitance generation, as well as easy transport of charge carriers, ions and electrons, within the composite electrode.[47]
• Manganide oxide intercalated composite electrode
As of 2013 a new composite electrode material with a high amount of pseudocapacitance achieved a specific capacitance of 1000 F/g and energy density of 110 Wh/kg. The layered intercalation compounds Na
xMnO
2 nanoflakes prepared directly through wet electrochemical process with Na(+) ions intercalated into MnO
2 interlayers. The nanoflake electrodes exhibit faster ionic diffusion with enhanced redox peaks.
• 3D porous graphene electrode
A graphene electrode material achieved a specific capacitance of 231 F/g, and an energy density of 98 Wh/kg was developed in 2013. This 3D porous graphene-based bulk material consists of mainly wrinkled single layer graphene sheets a few nanometers in size, with at least some covalent bonds.
• 2-dimensional graphene nanosheet electrode for line-filtering
The charge carriers in vertically oriented graphene nanosheets can migrate more quickly into or out of the deeper structures of the electrode, increasing power density, reducing electrolytic resistances and with RC time constants of less than 200 microseconds. That makes them suitable for 100/120 Hz line filter applications replacing larger low voltage electrolytic capacitors.[61]
• Quantum effect supercapacitor
Quantum electrodynamics offers potential for the further increase of energy and power density. These quantum supercapacitors exhibit nanoclusters of dipolar metal oxides in a rutile structure such as TiO
2 or TAO
2 with a cluster size of up to about 30 nm. Energy storage is mainly provided by loading the cluster with electrons, using the wave-particle duality of electrons. The charge waves tunnel the nanostructured material and collect in the cluster, which exhibits high energy and power density. Quantum supercapacitors theoretically offer energy densities up to 480 Wh/kg
Real genius Indian, how much time this technology will take to come in market.