Energy

||Batteries

The basic components of a battery include:

  1. an electrolyte to provide electrons,
  2. an anode to discharge those electrons, and
  3. a cathode to receive them.

A pure lithium anode would significantly improve efficiency over currently available lithium electrolyte products with graphite of Si as the anode. One barrier to a lithium anode has been the swelling of lithium and the creation of dendrites that short the circuit and reduce battery life. A protective layer for a lithium metal anode is under development that needs to be chemically stable to protect against the chemical reactions with the electrolyte and mechanically strong to withstand the swelling.

Sodium is more environmentally benign than lithium as used in rechargeable batteries. Diffusing sodium ions through tin anodes often weaken the tin’s connection to its base material. However, the wood fibers are soft enough to serve as a mechanical buffer, and thus can accommodate the swelling and shrinking of the tin nanocoating up to 400 cycles. Additionally, wood fibers that make up a tree once held mineral-rich water, and so are ideal for storing liquid electrolytes.

||Flexible electronics

In an effort to replace silicon wafers, flexible polymers (i.e. organic field-effect transistors) need to pack into crystalline structures containing regular pathways for charge carriers. It is found that fluorenone carbonyl units have the following advantages:

  • makes electrons in the co-polymer’s highest energy states less accessible and therefore less susceptible to air-based impurities;
  • helps to stick to aromatic hydrogen atoms; and
  • improves solid state packing.

Flexible and wearable electronics may allow for a wide variety of human-machine interfacing applications. To overcome the difficulty of using brittle Si, the textile may the dipped into an aluminum solution that will form metal fibrous networks with the help of a Ti catalyst. Polymers may also have embedded NPs of gold that align as they the material is stretched. This provides the material a conductivity of 35 S/cm even when stretched at 5.8 times its original length (enough for small devices).

Graphene inks are also an alternative and can be printed on paper. Carbon in general is an attractive material because wires made from carbon are 10 times lighter and up to 30 times stronger than copper. Carbon wires also have the added benefits of corrosion resistance, a higher current capacity and lower losses in transmission efficiency with increasing temperature. Their conductivity is yet to match copper, however, due to the discontinuity of the individual CNTs.

||Friction

Super-lubricity is a theoretical concept  in overcoming friction on the microscopic scale. It is found that along a twist boundary (shear interface) of carbon, the atoms are misaligned which avoids crystal locking. The result is being able to translate at 25m/s (90km/h) on a micrometre squared area.

Friction is also found to be tunable at the nanoscale. By varying the thickness of the SiO2 layer, the forces experienced by AFM scanning could vary up to 30%.

||Hydrogen

Unlike hydrocarbon fuels, such as oil, coal and natural gas, where carbon dioxide and other contaminants are released into the atmosphere when used, hydrogen fuel usage produces pure water as the only byproduct. Nanoscale water electrosis may be facilitated by nanoparticles that mimic photosynthesis. In essence, an efficient separation of hydrogen from water occurs.

||Light

Biological systems on Earth demand light for energy, including the critical photosynthesis process. Solar energy harvesting is a ready application of nanomaterials. This is because it has most to do with surface science. The bandgap of a material is found to be affected by nanostructuring. For example, arsenic NP absorption from deep infrared to green is controllable by varying degrees of dimensional structuring. Core-shell gold NPs have also been found to convert a broad visible-invisible spectrum of light into heat that can be used for steam generation.

Synthesize the DNA of an Arabidopsis plant with genes from a firefly, and the result is natural luminosity. May or may not replace street lamps, let alone a table lamp, but applications are still vast for low cost or free electricity.


||Computers

Skyrmions are new magnetic structures which were discovered as a grid of magnetic eddies in a silicon manganese crystal. Individual eddies can also be generated on surfaces and moved electronically. Researchers are interested in using skyrmions to transfer magnetic information directly to materials through electric current alone, since they require 100 000 times less current and significantly less atoms per bit of information. Such an advancement would result in more compact and energy-efficient computers, but the method is still limited to very low temperatures.

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