LITHIUM ION BATTERIES TO HYBRID CARS 

A lithium-ion battery or LIB is an electrochemical cell which produces an electric current from energy released by a spontaneous redox reaction. Electrochemical cells have two conductive electrodes, the anode and the cathode. The anode is defined as the electrode where oxidation occurs and the cathode is the electrode where the reduction takes place. Electrodes can be made from any sufficiently conductive materials, such as metals, semiconductors, graphite, and even conductive polymers. In between these electrodes is the electrolyte, which contains ions that can freely move.

Lithium-ion batteryis a solid state battery operating using a solid electrolyte. Lithium polymer batteries are an example of this; a graphite bar acts as the anode, a bar of lithium cobaltate acts as the cathode, and a polymer, swollen with a lithium salt, allows the passage of ions and serves as the electrolyte. In this cell, the carbon in the anode can reversibly form a lithium-carbon alloy. During the discharging process, lithium ions spontaneously leave the lithium cobaltate cathode and travel through the polymer into the carbon anode forming the alloy. This flow of positive lithium ions is the electrical current that the battery provides. By charging the cell, the lithium dissociates from the alloy and travels back into the cathode. The advantage of this kind of battery is that Lithium possesses the highest negative value of standard reduction potential. It is also a light metal and therefore less mass is required to generate 1 mole of electrons.

Lithium-ion batteries are common in consumer electronics. They are one of the most popular types of rechargeable battery for portable electronics, with one of the best energy densities, no memory effect, and a slow loss of charge when not in use. Beyond consumer electronics, LIBs are also growing in popularity for military, electric vehicle, and aerospace applications.

On Dec. 16, 2005, Toyota announced that they would accelerate development of lithium batteries for use in their hybrid cars. A hybrid car uses two different power sources. They are an electric motor and almost always an internal-combustion engine. In the hybrid design, an electric motor or several electric motors power the car, and a combustion engine keeps the batteries charged and assists when more power is needed e.g. for sudden acceleration. That's a clear sign of how important battery power may become for the auto industry.

There are many extremely important electrochemical processes in both nature and industry, like the coating of objects with metals or metal oxides through electrodeposition and the detection of alcohol in drunken drivers through the redox reaction of ethanol. The generation of energy through the process of photosynthesis is also an example of an electrochemical process. Application of electrochemistry is widely discussed in WACE syllabus. Tutors in Melbourne cover this chapter elaborately for better understanding of the students. For further help with electrochemistry please visit iExel.