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Lithium-Ion batteries

2021 NOV 30

Preliminary   > Science and Technology   >   Energy   >   Innovation and New technologies

Why in news?

  • A fabrication lab for Lithium-Ion batteries will soon be set up in Bangalore in an attempt to boost up-scaling and commercialisation of the technology.

About lithium-ion battery:

  • A lithium-ion battery is a family of rechargeable battery types in which lithium ions move from the negative electrode to the positive electrode during discharge and back when charging.
  • Li-ion batteries have a high energy density, no memory effect and low self-discharge.

Components:

  • Anode, cathode, electrolyte and separator are the main components of a lithium-ion (rechargeable) battery.
  • The two electrodes are immersed in the electrolyte and are separated by the separator.
  • The anode is usually made up of graphite (carbon).
  • Carbon graphite has a layered structure that can store the lithium ions in between its layers.
  • The cathode is made up of a combination of lithium-cobalt.
  • Lithium is unstable in the element form; hence the combination lithium-cobalt oxide is used for the cathode.
  • Cathode plays an important role in determining the energy density of a Li-ion battery.
  • The higher amount of lithium, bigger the capacity.

How it works?

  • Both electrodes in a li-ion battery can intercalate or ‘absorb’ lithium ions.
  • When the battery is being charged, lithium ions are absorbed (stored) in the anode.
  • During discharge, lithium ions naturally flow back to the cathode through the electrolyte.
  • This creates free electrons in the anode which move along the wire generating electricity.
  • The process (to and fro movement of lithium-ion) repeats with each charge and discharge cycles.
  • Electrolyte (lithium salt) enables the movement of lithium ions between the electrodes.
  • The separator functions as a physical barrier keeping cathode and anode apart.
  • It prevents the direct flow of electrons and lets only the ions pass through.
  • While the cathode determines the performance of a battery, electrolyte and separator determine its safety.
  • Permeable polymer membranes such as polyethylene (PE) and polypropylene (PP) are used as separators.

Why lithium?

  • Lithium is the lightest metal and a powerful reducing agent (willing to donate its electrons).
  • Lithium-ion batteries capitalize on the strong reducing potential of lithium ions to power the redox reaction — reduction at the cathode, oxidation at the anode.

Applications

  • Lithium-ion batteries have become very commonplace: from everyday electronic products such as cell phones to electric vehicles.
  • They have applications in electronic gadgets, tele-communication, aerospace, industrial applications etc.

Disadvantages of Li-ion Batteries:

  • Long charging times.
  • Safety issues as instances of batteries catching fires have been there.
  • Expensive to manufacture.
  • While the Li-ion batteries are seen as sufficiently efficient for applications such as phones and laptops, in case of EVs, these cells still lack the range that would make them a viable alternative to internal combustion engines.

Lithium in India:

  • India does not have enough lithium reserves for manufacturing lithium-ion batteries
  • China controls most of the lithium supply across the world.

Add ons:

  • John B Goodenough, M Stanley Whittingham from the US and Akira Yoshino from Japan won the Nobel Prize in Chemistry 2019 “for the development of rechargeable lithium-ion batteries”.

PRELIMS QUESTION

With reference to ‘lithium-ion battery’,consider the following statements:

1. It is a type of rechargeable battery

2. They have no memory effect and have low self-discharge

3. They contain flammable electrolytes

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1,2 and 3

Answer