Lithium Ion Battery Electrolyte Solvent

Lithium ion batteries are becoming more and more popular since the first one was made in 1970. The earlier lithium batteries were not as effective as the batteries nowadays. The lithium ion batteries have been become better and better with time so we can expect them to be even better with time. There are a lot of people who use lithium ion batteries in their phones and laptops and they have no idea how they work or what they use. We are going to discuss something about lithium ion batteries and when you leave here you will be wiser than you were before reading this article.

Lithium Ion Electrolyte Materials

The lithium ion batteries usually have electrolytes that play a role of transporting positive lithium ions between the anode and the cathode. Just like athletes, lithium ion batteries need electrolytes. If you are still confused about what are electrolytes are then you should know that this name comes from a Greek word lytos which means it can be united or loosened. In short electrolytes are conducting solutions found in a lithium ion batteries. Some of the materials that are used to make lithium ion electrolytes include:

· Soluble Salts.

· Organic Solvents.

· Additives.

How does lithium ion electrolyte work?

Electrolytes as we have established serves as a catalyst that makes the battery conductive by enabling movement of the ions from the cathode to the anode when charging and when it is discharging. We might be talking about ions and you are still confused what ions are, in simple terms ions are atoms that are electronically charged and have lost or gained electrons. We have seen that the electrolytes are composed of soluble salts, solvents, and other additives. But how does a lithium ion electrolyte work? We will examine how this electrolytes works and after reading this article you will have learnt a new thing.

The lithium ion batteries uses gel, liquid or dry polymer electrolyte. The liquid electrolytes are usually flammable and it is made of lithium salts that have organic solvents that are more of the same as ethylene carbonate. When this solution is mixed with diverse carbonates, they provide a better conductivity and the temperature range is expanded. Sometimes other salts are added to help reduce gassing as well as improve the cycling of high temperature.

The lithium batteries that use gel as their electrolytes, usually receive so many additives to ensure that the conductivity is increased. The same case happens to the lithium ion batteries that uses dry polymer electrolytes, lots of additives are added to ensure maximum conductivity. A real dry polymer can only become conductive at very high temperature and it is because of this that this battery is no longer available for commercial use. The additives are used to increase the longevity and also provide the batteries with some unique characteristics. Each company that manufactures this batteries has their own recipes and that’s why you find that some lithium ion batteries are of higher quality compared to others.

The electrolyte is expected to be stable but this is not how lithium ion batteries work. A passivation film forms on the anode of the battery (solid electrolyte interface SEI). The layer is the one that separates the cathode from the anode but at the same time allow ions to pass. It is more of a separator than an electrolyte. The solid electrolyte interface must form in order for a lithium ion battery to work. This layer gives a lithium ion battery a longer life but it do cause capacity reduction. That’s why nowadays lithium ion batteries don’t have huge capacities as the ones that used lithium metals back in the days. The electrolyte oxidation that occurs on the cathode also reduces the capacity of a lithium ion battery.

The SEI can become too restrictive and it is because of this that additives are mixed with the electrolyte to make sure they are consumed during the formation of the layer. It is difficult if not impossible to trace the presence of the additives when conducting a forensic evaluation. The additives are a secret of the manufacturers and they are the only ones know how much they add and what composition they use.

One of the known additive is vinylene carbonate, which is used to improve the cycle of life of a lithium ion battery mostly during high temperatures. Vinylene carbonate maintains a stable SEI formation on the anode and prevents oxidation on the cathode.

The SEI layer can only break down on a cell if the temperature is over 70 degrees. The flammability of the lithium ion electrolyte has been a topic of discussion as this electrolytes can be very flammable if given a chance.

When the liquid electrolyte starts drying up it means that the battery is dying and when the liquid is gone then the battery is dead.

What is the best lithium ion battery electrolyte?

There are several electrolytes that are used in different batteries and some of the best ones include:

· Nonaqueous electrolytes. This electrolytes made by the Pacific Northwest national laboratory in USA have desirable salt properties and they have the capability of forming an excellent SEI layer. They use LiPF6 salts which are very effective.

· Nonaqueous electrolytes with advances in solvents. This electrolytes are made in japan and they have excellent conductivity as well as high electrochemical stability. They have a wide range of operating temperature making them very safe for usage by lithium ion battery manufacturers.

Conclusion

Lithium ion battery have become very common nowadays. The batteries we use today are so much better than the batteries that were used in the past. With advancement of technology the batteries they will keep on getting better and better. The electrolytes that are used in different batteries are unique and each and every manufacturer has their own recipe of making their lithium ion electrolytes.