What Are the Latest Developments in Battery Technology?
Storing charges is relatively simple, but certain limitations impact their usage. Sometimes we need size or safety and so have to turn to science for different ways to meet this. Below are some new types of batteries that may one day power something in your life…
The battle for smaller and smaller technology goes on, and one development has exciting possibilities for the future. Scientists have developed a battery that is a conglomeration of smaller nanobatteries which provide a larger area for charging while decreasing transfer distances that will allow for the battery to go through more charging cycles. Each of the nanobatteries is a nanotube with two electrodes encapsulating a liquid electrolyte that has nanopores composed of anodic aluminum with endpoints made of either V2O5 or a variant of it to make a cathode and an anode. This battery produced about 80 microamp-hours per gram in terms of storage capacity and had about 80% of the capacity to store charge after 1000 charging cycles. These all make the new battery about 3 times better than its prior nano-counterpart, a major step in miniaturization of technology (Saxena “New”).
In another advancement in nanotechnology, a nanobattery was developed by the team at Drexel’s Department of Materials Science and Engineering. They created a layering technique where 1-2 atomic layers of some kind of transition metal are topped and bottomed by another metal, with carbon acting like the connectors between them. This material has excellent energy storage capabilities, and has the added benefit of easy shape manipulation and can be used to make as little as 25 new materials (Austin-Morgan).
For this type of battery, one needs to think about electron streams. In a redox-flow battery, two separate regions filled with an organic liquid electrolyte are allowed to exchange ions between them via a membrane which divides the two. This membrane is special, because it has to allow only for the flow of electrons and not the particles themselves. Like the cathode-anode analogy with a normal battery, one tank is negative in charge and so it an anolyte while the positive tank is the catholyte. The liquid nature is the key here, because it allows for scaling to sizes on a large scale. One specific redox-flow battery that has been built involves polymers, salt for the electrolytes, and a dialysis membrane to allow the flow. The anolyte was a 4,4 bipuridine-based compound while the catholyte was a TEMPO radical-based compound, and with both having low viscosity they are easy to work with. After a 10,000 charge-discharge cycle was complete, it was found that the membrane performed well, only allowing trace cross-troughs. And as for the performance? The battery was capable of 0.8 to 1.35 volts, with an efficiency of 75 to 80%. Good signs for sure, so keep an eye out for this emergent battery type (Saxena “A Recipe”).
Solid Lithium Batteries
Thus far we have talked about liquid-based electrolytes, but are there solid ones? Normal lithium batteries use liquids as their electrolytes, for they are an excellent solvent and allow easy ion transportation (and in fact can improve performance because of the structured nature). But there is a price to pay for that ease: when they leak, it’s incredibly reactive to the air and therefore destructive to the environment. But a solid electrolyte option was developed by Toyota that performs as well as their liquid counterparts. The catch is that the material must be a crystal, for the lattice structure it is made of provides the easy pathways the ions desire. Two such examples of these crystals are Li9.54Si1.74P1.44S11.7C0.3 and Li9.6P3S12, and most of the batteries could work from -30o Celsius to 100o Celsius, better than the liquids. The solid options could also go through a charge/discharge cycle in 7 minutes. After 500 cycles, the efficiency of the battery was 75% that it initially was (Timmer “New”).
Surprisingly, heating up a battery can improve its life (which is weird if you have ever had a hot phone). You see, batteries over time develop dendrites, or long filaments that result from the recharging cycle of a battery transporting ions between cathode and anode. This transference builds impurities that over time extend out and eventually short-circuit. Researchers as the California Institute of Technology found that temperatures of 55 Celsius reduced dendrite lengths by up to 36 percent because the heat causes the atoms to displace favorably to reconfigure and lower the dendrites. This means the battery can possibly last longer (Bendi).
Interestingly, pieces of graphene (that magical carbon compound that continues to impress scientists with its properties) into a plastics material increases its electric capacity. Turns out, they can generate large electric fields according to work by Tanja Schilling (Faculty of Science, Technology, and Communication of the University of Luxembourg). It acts like a liquid crystal which when given a charge causes the flakes to rearrange so that the transference of charge is inhibited but instead causes the charge to grow. This gives it an interesting edge over normal batteries because we can maybe flex the storing capacity to certain desire (Schluter).
Something you don't hear too often are magnesium batteries, and really we should. They are a safer alternative to lithium batteries because it takes a higher temperature to melt them, but their ability to store charge isn't as good because of the difficulty in breaking magnesium-chlorine bonding and the resulting slow pace of the magnesium ions travelling. That changed after work by Yan Yao (University of Houston) and Hyun Deong Yoo found a way to attach magnesium mono-chlorine to a desired material. This bonding proves to be easier to work with and provides nearly four times the cathode capacity of previous magnesium batteries. The voltage is still an issue, with only one volt being capable as opposed to the three to four a lithium battery can produce (Kever).
Another interesting battery material is aluminum, for it is cheap and readily available. However, the electrolytes involved with it are really active and so a tough material is needed to interface with it. Scientists from ETH Zurich and Empa found that titanium nitride offers a high level of conductivity while standing up to the electrolytes. To top it off, the batteries can be made into thin strips and applied at will. Another advancement was found with polypyrene, whose hydrocarbon chains allow for a positive terminal to transfer charges easily (Kovalenko).
In a separate study, Sarbajit Banerjee (Texas A&M University) and team was able were able to develop a "metal-oxide magnesium battery cathode material" that also shows promise. They started by looking at vanadium pentoxide as a template for how their magnesium battery was to be distributed throughout it. The design maximizes electron travel paths via metastability, encouraging elections to travel on paths that would otherwise prove to be too challenging to the material we work with (Hutchins).
Austin-Morgan, Tom. “Atomic layers ‘sandwiched’ to make new materials for energy storage.” Newelectronics.co.uk. Findlay Media LTD, 17 Aug. 2015. Web. 10 Sept. 2018.
Bardi, Jason Socrates. "Extending a Battery's Lifetime with Heat." 05 Oct. 2015. Web. 08 Mar. 2019.
Hutchins, Shana. "Texas A&M develops new type of powerful battery." innovations-report.com. innovations report, 06 Feb. 2018. Web. 16 Apr. 2019.
Kever, Jeannie. "Researchers report breakthrough in magnesium batteries." innovations-report.com. innovations report, 25 Aug. 2017. Web. 11 Apr. 2019.
Kovalenko, Maksym. "New materials for sustainable, low-cost batteries." innovations-report.com. innovations report, 02 May 2018. Web. 30 Apr. 2019.
Saxena, Shalini. “A recipe for an affordable, safe, and scalable flow battery.” Arstechnica.com. Conte Nast., 31 Oct. 2015. Web. 10 Sept. 2018.
---. “New battery composed of lots of nanobatteries.” Arstechnica.com. Conte Nast., 22 Nov. 2014. Web. 07 Sept. 2018.
Schluter, Britta. "Physicists discover material for a more efficient energy storage." 18 Dec. 2015. Web. 20 Mar. 2019.
Timmer, John. “New lithium battery ditches solvents, reaches supercapacitor rates.” Arstechnica.com. Conte Nast., 21 Mar. 2016. Web. 11 Sept. 2018.
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© 2018 Leonard Kelley