Anode Materials in Li-Ion Batteries - Research Paper Example

? Anode Materials in Li-ion batteries This research paper aims to study about Anode Materials used particularly in Li-ion Batteries. Different materials have entirely different chemical properties and hence some of them are suitable for Li-ion batteries while others are not. An anode material not only enhances the productivity of batteries but it also makes it less costly. To comprehend the logic behind the use of anode material it is important to first understand the properties of materials used while analyzing their specific purposes. Moreover, future development requires different ways of improving the anode materials which shall be discussed in this paper. The paper would be of prime importance for engineers and electronic professionals dealing in Li-ion Batteries whereas it will also benefit other researchers and people who are interesting in learning about the anode materials. Description Li-ion Battery is also known as Lithium ion battery which is primarily used as rechargeable support to different electronic devices. Currently its market sell is around 11 billion which is expected to reach 60 billion by 2020 (Li-ion batteries). Due to the technological advancements human lives are now prominently dominated by electronic gadgets and other devices. These portable electronic items require immense support of rechargeable batteries and hence Lithium ion Battery performs a very crucial role in the technological development. However, these batteries are associated with another important factor which directly impacts their performance and efficiency i.e. the properties of Anode materials used (Li-ion batteries). Source: Futurity 1 Li-ion batteries function on the basis of discharge and recharge of lithium ions. When Lithium ions are transferred from anode to cathode the Li-ion battery discharges. Subsequently it is attached to a socket in order to recharge the ions which now travel in opposite direction i.e. from cathode to anode. The property of materials used in anode substantially affects the capacity and performance of the battery. If some lapses occur in the performance of batteries then particular anode materials are replaced with substances having more capacity, density, battery life cycle, life span of the charge etc. (Li-ion batteries). The chemical reactions taking place in Li-ion batteries are presented below: Complete reaction in a cell of Li-ion Battery At Anode At Cathode The following diagram depicts the Li-ion battery in a functioning state and the movement of ions can be closely observed. Source: Nexeon 1 Properties of Anode Materials Different anode materials are used in Lithium batteries depending upon the requirement of chargeable devices. The selection of material is further associated with the capacity constraints and the overall life of the battery. Graphite is commercially used in Li-ion battery. The first generation of Li-ion batteries was primarily operated with graphite anode material because it was found beneficial in placing the Lithium ions in to variable layers. Later on these materials were changed due to the limited capacity of graphite to store charge i.e. 300mAhg-1 (Li-ion batteries). Extensive research was conducted so as to identify other suitable materials which could be placed at anode and consequently silicon was examined to be more productive than graphite. Silicon gives the maximum gravimetric capacity while increasing the battery life. The volumetric capacity of anode significantly enhances with the insertion of lithium ions take in to the silicon material (Li-ion batteries). When a Li-ion battery is charged which is primarily designed with silicon anode material then the lithium ions enter the silicon ions subsequently increasing the volume by 400%. On the other hand when the battery discharges the lithium ions are removed from silicon material hence decreasing the overall volume. Although silicon has found to be more efficient than the graphite anodes but the continuous contraction and expansion ultimately causes the material to lose its productivity. Due to the fractured silicon ions the conducting power of batteries are greatly affected and hence the conventional life of such anode materials is usually very short (Li-ion batteries). Currently the InVO4 has been greatly examined for its efficiency and use as an anode material in Li-ion Battery. Research indicates that the theoretical capacity of InVO4 actually persuaded the scientists to use it in rechargeable batteries. However, until now the impact of preparation procedures, morphological condition and the storage capacity of InVO4 has not been studied significantly. InVO4 is typically prepared with the incorporation of five distinguished methods i.e. combustion of urea, the solid state, precipitation, polymer precursor and ball milling (Reddy). Following is the representation of InVO4 during its preparation. Source: Applied Materials and Interfaces 1 Studies indicate that urea combustion is the most suitable preparation method for InVO4 as it generated the most extensive electrochemical results. Moreover, it has advance capacity i.e. 1241 mAhg-1 which does not vanish off between 2nd to 50th cycles. Precipitation method was also found somewhat beneficial because it generated an overall charge capacity of 1002 mAhg-1 for the Li-ion Batteries (Reddy). Anodes of the Lithium Batteries perform the most crucial job in the entire circuit. Therefore researchers have been trying to locate the anode material with excellent performance, capacity and long life. Ribbons of Graphene are also experimented in this regard and the tests indicate positive results. Graphene nanoribbons are basically very small atoms which are uniquely thicker and longer as compared to their width. These are shown in the below diagram (Williams-Rice). Source: Futurity 2 The significant increase in the use of different portable devices, smart phones, computers etc. have actually impacted the demand of Li-ion batteries. This primarily happened because today consumers require rechargeable batteries with longer durations. In the latest experiment the Graphene nanoribbons are combined with small particles of tin oxide in order to make a mixture. This is subsequently combined with the gum binding having glucose as the main ingredient and the little bit water. The mixture is placed on a collector and later encased in a battery (Williams-Rice). The graphene ribbons have an internal capacity of around 1520 mAhg-1 and unlike silicon it does not get fractured on the continuous usage. For instance, if the batteries with graphene ribbons undergo repeated cycles of discharge and recharge then they transform into a solid material with 825mAhg-1. Hence they have been recognized to possess the ability of resolving expansion problem and maintaining the essential conducting power over many cycles. Moreover, it is a very light weight material and extremely thin which makes the Li-ion battery easy to carry anywhere (Williams-Rice). Purpose and use of Anode Material The anode is basically a composition of negatively charged ions in a lithium battery which attract the positive ions from cathode during the charging phase. On the other hand when the battery is discharged the bond of anode material and lithium ions break and consequently the battery losses it electrical power. Hence whatever the material is used at the anode it has to undergo frequent contraction and relaxation, for instance, on daily or weekly basis. This challenges the transforming ability of the material and hence it requires being very strong in terms of volume and capacity (Li-ion batteries). Once the anode material starts losing its power then its capacity in milliamp hours per gram automatically decreases and later results in complete fracture of the material as in the case of silicon. The primary aim of different researchers and scientists is to figure out the anode material with maximum gravimetric capacity, volumetric strength and the ability to contract and relax over a longer period of time. Ways of improving anode in batteries by using new materials Considering the distinguished usage and purpose of anode material few other experiments have been conducted to identify the best suitable material for the Li-ion batteries. In addition to the change in material the researchers also focused over the traditional design of Lithium batteries which according to them causes short life span and fracture in anode material. As discussed above that in order to retain electric charge the anode material swells up because of storing lithium ions. Thus the storage of lithium ions is the fundamental factor which challenges the capacity of battery as it requires extensive expansion power while having reduced impact of continuous discharge recharge cycles (A Better Anode Design To Improve Lithium-Ion Batteries). Since graphite lacks the expansion power and silicon does not have the ability to resist frequent contraction and relaxation therefore the scientists decided to use a mixture of silicon, binder containing polymer and carbon. Although this closely resembles the traditional approach but the researchers have tailored the polymer by increasing its storing power of lithium ions. Eventually the same silicon mixture now can bear the stress of shrinkage more than three times. The newly tailored polymers are less costly than the previously used binders and hence they can be easily adopted by the battery manufacturing companies. These are scientifically known as conducting polymer bases with polyfluorene (A Better Anode Design To Improve Lithium-Ion Batteries.). Following graphic representation illustrates the difference between traditionally used silicon material and the silicon with newly prepared polymers. Source: Berkeley Lab 1 Below is the reflection of how polyfluorene works in a Li-ion battery. Source: Berkeley Lab 2 The following picture depicts the increase in electronic state of silicon mixture due to the use of new polymers. Source: Berkeley Lab 3 Conclusion Lithium Battery is one of the most essential components for operating almost all of the portable electronic devices especially those which have an inbuilt recharging system. In the contemporary world smart phones, laptops, cameras etc. have gained the position of widely consumed products and so the demand for Lithium batteries is continuously increasing. The invention of electronic cars and their increasing use in the near future will immensely augment the use of rechargeable batteries. The performance of Li-ion batteries is largely dependent upon the anode material and hence the scientists and researchers are now investigating more feasible materials to be used as anode. Since anode is responsible to attract and restore lithium ions from cathode therefore the gravimetric capacity and the limited volume of the material creates substantial hindrances in the activity of the battery. Initially graphite was used as anode material but since it has a low expansion power therefore silicon replaced it. Although silicon was able to expand thrice as compared to graphite but on the whole it had a low resistance of undergoing frequent expansion and contraction cycles. Thereafter researchers examined the InVO4 and graphene nanoribbons which were found more productive than the silicon anode material. However, today some of the researchers are also experimenting on the silicon material with newly tailored polymers in order to increase their resistance and capacity. Works Cited A Better Anode Design To Improve Lithium-Ion Batteries. Lawrence Berkeley National Laboratory. 2013. Web. 6 Oct 2013. Li-ion batteries. Nexeon. 2013. Web. 6 Oct 2013. Reddy, M.V., Bryan Lee Wei Wen, Kian Ping Loh and B. V. R. Chowdari. "Energy Storage Studies on InVO4 as High Performance Anode Material for Li-Ion Batteries." ACS Applied Materials and Interfaces (2013): 7777–7785. Williams-Rice, Mike. Graphene Ribbons Improve Lithium Ion Batteries. Futurity: Science and Technology. 2013. Web. 6 Oct 2013. Read More