Li-ion batteries are secondary batteries with a Lithium anode and Li+ ions dissolved in carbon. The cathode material is composed of chemicals that liberate lithium. With a high energy density and low self-discharge, “they are one of the most widely used rechargeable battery types for portable electronics. The lithium-ion battery has three times more energy than lead-acid or NiCd batteries of the same size and weight, and twice as much energy as NiMH batteries. For the same amount of energy, it is half the size and weight of a NiMH battery. These qualities have made lithium-ion batteries a key component in the advancement of the technological revolution. It has enabled the development of mobile phones with a wide range of features and powerful portable PCs. Li-ion batteries can also operate well in a wide temperature range, from -20 degrees Celsius to +50 degrees Celsius, and they can withstand hundreds of cycles of charging and discharging. It shouldn't be shocking that more research and development is being done on the lithium-ion system than any other system, or that the use of lithium-ion batteries is growing more quickly than the use of any other portable source of energy. Since the development of electrotechnology, electrostatic capacitors have been a crucial component of electronic circuits since they are the simplest and most literal method to store electrical energy. Supercapacitors have been used to complement or replace batteries in applications requiring energy storage and/or load-leveling, such as portable electronic devices, plug-in hybrid electric cars, wind farms, and long-term continuous circuits. Wind farms are one example of these kinds of uses. Due to their high cost and low energy density, supercapacitors have less market penetration when compared to batteries. Supercapacitors have a high power density, however this is the case. In essence, a supercapacitor is an electrochemical capacitor with a very high energy density. It typically comprises of two conductors (cathode and anode) that are separated by an insulator. Activated carbon-based conventional symmetric supercapacitors have intrinsically low energy density. Producing an asymmetric supercapacitor with a carbon cathode and transition metal oxide anode could provide a solution. However, early attempts at developing such supercapacitors were constrained by kinetic” considerations to extremely thin electrode sheets, resulting in a relatively poor energy density.

Li-ion batteries, energy density, supercapacitors, Lithium anode, chemical energy.