Over decades, we have seen a lot of improvements in almost all forms of technologies, one of the most noticeable part, which has no change since so long is “energy storage device” called “battery”. If you look at the technological industry, all developments are being done to use the energy contained in the batteries efficiently. But on the market we didn’t experience any change, when it comes to batteries, only the components that use batteries are made efficient towards energy consumption.
If new technologies rise, which can make energy storage better, then we don’t have to compromise on other components in a device due to batteries. For example the size of the device increase due to batteries, explosions of the batteries can be avoided if the batteries won’t contain liquid in it(like, we use lithium, which explodes when moisture comes in contact).
Battery is that which stores chemical charge and converts it into electricity. Every battery has a cathode(+), anode(-) and an electrolyte. Cathode wants electrons, anode gives electrons and an electrolyte is that which helps ions to move between anode and cathode. This flow of electrons create electricity. Over the years we have found various ways of creating and storing electricity, like electricity from a lemon, banana etc… Most of those works on the above concept.
▪ A lot of research is being done on this particular topic, but most of those alternatives don’t have sufficient potential to get commercialized. Few alternatives that can be expected on the market soon are:
▪ Graphene Super-capacitors.
▪ Solid state batteries.
Before getting into Graphene super-Capacitor, let’s see what are super capacitors and capacitor s are!
▪ Basically a capacitor charges and discharges quickly. A basic capacitor usually consists of two metal plates, separated by an insulator (like air or a plastic film). During charging, electrons accumulate on one conductor and depart from the other. One side gains a negative charge while the other side builds a positive one. The insulator disturbs the natural pull of the negative charge towards the positive one, and that tension creates an electric field. Once electrons are given a path to the other side, discharge occurs.
▪ Supercapacitors also contain two metal plates, two electrodes are coated with a porous material known as activated carbon. They are immersed in an electrolyte made of positive and negative ions dissolved in a solvent. One plate is positive and the other is negative. During charging, ions from the electrolyte accumulate on the surface of each carbon-coated plate. Supercapacitors also store energy in an electric field that is formed between two oppositely charged particles, only they have the electrolyte in which an equal number of positive and negative ions is uniformly dispersed. Thus, during charging, each electrode ends up having two layers of charge coating (electric double-layer).
▪ Graphene is a thin layer of pure carbon, tightly packed and bonded together in a hexagonal honeycomb lattice. It is widely regarded as a “wonder material” because, it is the thinnest compound known to man at one atom thick, as well as the best known conductor. It also has amazing strength and light absorption traits and is even considered ecologically friendly and sustainable as carbon is widespread in nature and part of the human body.
▪ It is often suggested as a replacement for activated carbon in supercapacitors, in part due to its high relative surface area, which is even more substantial than that of activated carbon. The surface area is one of the limitations of capacitance and a higher surface area means a better electrostatic charge storage. In addition, graphene based supercapacitors will utilize its lightweight nature, elastic properties and mechanical strength.
▪ Graphene Super-capacitor has advantages of both Li-ion battery and a capacitor. Fast charging of a capacitor and the slow discharging of a battery can be obtained in a super-capacitor.
Solid state super capacitor:
▪ Almost all the batteries we use have a liquid or a gel in them. Now, when it comes to solid state batteries, the liquid or the gel portion is replaced with a solid. This can avoid battery explosions completely.
▪ The main difference between Li-ion batteries and solid state batteries is that the former uses a liquid electrolytic solution to regulate the flow of current, while solid-state batteries opt for a solid electrolyte. A battery’s electrolyte is a conductive chemical mixture that allows the flow of current between the anode and cathode.
How Solid state super capacitor works?
▪ solid state batteries use redox reactions to store and deliver energy. Oxidation occurs at the anode, reduction occurs at the cathode and the battery is able to use this phenomenon to store energy (charge) and release it (discharge) as necessary. During discharge, ions travel through an ion-conductive solid matrix instead of the ionic salt saturated solvent state of typical liquid electrolytes.
▪ Solid state electrolytes are fast ion conductors solids that allow ions to move freely throughout the solids crystalline matrix. Fast ion conductors are best thought of as a material that lies between crystalline solids that possess a regular structure with fixed ions and structure-less liquid electrolytes with freely flowing ions. Solid electrolytes often come in the form of gels, glasses and crystals with novel internal structures. In solid state batteries, solid electrolytes must meet a combination of high ionic conductivity, low internal resistance and high electronic resistance. The higher the ionic conductivity is the better the power density and the lower the internal resistance of the battery. The better insulating the solid electrolyte is to electrons, the lower the self-discharge rate and the higher the charge retention. Choice of solid electrolyte depends on the chemistry of the battery, and the ions available for conduction. In the case of lithium ion solid state batteries, a solid electrolyte like LiI/Al2O3 is an excellent Li+ conductor.
The concept of solid state batteries are around for so long now, but the technology is still in research grounds.
Many technological industries are working in this new technology. It was old that, samsung is working on this.
There is a company called Sakti3 in Michigan, exclusively working on solid state batteries. A British electronics giant Dyson invested millions of dollars on Sakti3. Not only that, so many other companies also showed interest and invested millions of dollars. This clearly shows how important this could become.
▪ So, with this I conclude that, very soon we might see a change in the way we treat and use technology interms of energy consumption. The graphene super-capacitors and solid state batteries are not the only ways to achieve these advantages, there are plenty of technologies under research. In my view these two are the closest to the market.