WORKING OF LITHIUM ION BATTERY

The lithium-ion battery is the power source for nearly all modern vehicles and devices. These days everyone is familiar with lithium-ion batteries but what makes them so special First of all each battery is made of smaller units called cells connected in series

      If we take a closer look and see how a battery works, The electric current reaches the cells via conductive surfaces, in this case, aluminum and copper on either side of the cells. we know that a cell consists of two electrodes an anode(-ve) and the cathode(+ve) respectively

     The cathode or +ve electrodes is made of very pure Li oxide the more uniform the composition the better the performance and longer the battery life is and the anode is located to opposite to cathode  and is made of graphite (which has layered structure) The battery is filled with electrolyte as transport medium so that li ions carrying charge can flow freely. this electrolyte must be extremely pure and free of water in order to ensure effective charge and discharge. To prevent short circuit  a layer is placed between two electrodes called separator  and tiny li ions pass from the cathode through the separator into layered graphite structure of anode where energy is stored now the battery is charged

        When the battery is discharging the li ions travel from anode to cathode with help of electrolyte through the separator

     The amount of energy available and the battery life are closely related to the quality of materials used

LI-ION the battery is a secondary battery and hence the reactions are reversible

CONSTRUCTION

     ANODE: LI COBALT OXIDE (LiCo2)

     CATHODE: Graphite

      ELECTROLYTE: KOH (POTASSIUM HYDROXIDE)

LI-ION BATTERY CAN BE REPRESENTED AS :

The accommodation of metal ions on the separator is known as interculation

During Discharging

LI COBALT OXIDE (LiCoO2) undergoes oxidation and releases Li-ions and these ions enter into graphite this process continues till all Li cobalt oxide is converted into ions

            And charging occurs when the battery is connected to an external power source. and in this case, the reaction gets reversed and the charging is done

At Anode :

LiCoO2 ------ Li(1-x)CoO2 + x Li+ + xe-

At Cathode :

xLi+ +xe- + C (graphite)  -------- xli-C

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 LiCoO2 + C (graphite) ---------- xLi-C + Li(1-x)CoO2 (Total equation)

Now let's talk about the future "the Graphene batteries"

Graphene-based batteries are being actively researched for many applications. The improved performance and life cycle advantages when developing graphene-based batteries over traditional metal ion batteries are well worth the resource investment. Tesla Motors provides a famous example of innovative companies actively pursuing graphene battery research and commercialization. The real graphene battery breakthroughs will be from graphene Li-ion hybrid chemistries incorporated into cathodes of LI sulfur cells This type of technology is still years away from commercialization and intensive research is going on
                   Graphene battery technology has a similar structure to traditional batteries in that they have 2 electrodes and an electrolyte solution to facilitate ion transfer the main difference between solid-state batteries and graphene-based batteries is in the composition of one or both electrodes. The change primarily lies in the cathode, but carbon allotropes can be used in the anode as well. The cathode in a traditional battery is purely composed of solid-state materials, whereas in graphene battery the cathode is a composite-hybrid material consisting of solid-state metallic materials and graphene. The amount of graphene in a composite can vary, depending upon the intended application. The amount of graphene incorporated  into the electrodes generally depends upon the performance requirements and is based upon the existing efficiencies or weakness of solid-state precursor material
Li-ION BATTERIES POWERED BY GRAPHENE INSTEAD OF GRAPHITE

Graphene-based batteries are quickly becoming more favorable than their graphite predecessors. Graphene batteries are an emerging technology that allows for increased electrode density, faster cycle times, as well as possessing the ability to hold the charge longer thus improving the battery’s lifespan. Graphite batteries are well-established and come in many forms. Similar to graphite, there are now various types of functional graphene derivative electrodes and researchers are discovering multiple benefits when compared to pure graphite electrodes

Here's the good news: we already have the lithium-graphene hybrid based batteries are in use now. one of the batteries with this technology which came into my notice is ELECJET APPOLO TRAVELER 5000 mah power bank It has the capacity of getting charged within 18 minutes

Lets Recap :
              Battery charging and discharging occur through the migration of Li ions between cathode and anode and exchange of electrons through doping and dedoping. More specifically, during charging Li is dedoped from cathodes consisting of Li-containing compounds,  and interlayers of carbon in anode are doped with lithium. Conversely during discharge Li is dedoped between carbon layers in the anode, and the compound layers in cathodes are doped with Li. Reactions occurring in Li-ion batteries employing LiCoO2 in cathode  and carbon in the anode is shown above