Electric Batteries and Electrochemical Cells | 16 Nov 2023

Source: TH

Why in News?

The electric batteries and electrochemical cell advancements have garnered significant attention for revolutionizing technology across sectors like transport and energy, steering us toward a sustainable future.

What are Electric Batteries and Electrochemical Cells?

• Electric Batteries:
  • An Electric battery is a device that stores chemical energy and converts it into electricity.
    • Batteries are made up of one or more electrochemical cells that are connected to external inputs and outputs.
  • Electric batteries have transformed our world, enabling the proliferation of motorization and wireless technology.
  • Major Applications:
    • Portable Electronics: Powering smartphones, laptops, tablets, and wearable devices.
    • Transportation: Driving electric vehicles (EVs) for both personal and public transportation, reducing reliance on fossil fuels.
    • Renewable Energy Storage: Storing energy generated by solar panels and wind turbines for later use.
    • Electricity for Remote Areas: Providing electricity in remote or off-grid locations where conventional power sources are unavailable or unreliable.
• Major Types of Batteries:
  • Solid-state battery: It is a battery that uses solid electrodes and a solid electrolyte instead of a liquid or polymer gel electrolyte.
    • Solid-state batteries are used in a variety of devices, including: pacemakers, radio frequency identifications (RFID) and wearable devices.
  • Nickel–Cadmium battery (Ni-Cd): They are used for Cordless electronic appliances, drills, camcorders and other small battery-operated devices requiring an even power discharge.
  • Alkaline Battery: This is a type of primary battery that uses zinc and manganese dioxide as electrodes.
    • It is used for applications that require low cost and reliable power, such as flashlights, toys, radios, and remote controls.
  • Lithium-ion Battery: The Li-ion battery's groundbreaking principles earned its developers the Nobel Prize in Chemistry in 2019, underscoring its profound impact in the 20th and 21st centuries.
    • Li-ion batteries are versatile, powering portable devices like phones and laptops as well as fueling electric vehicles such as cars and bikes.
• Electrochemical Cells:
  • Electrochemical cells are devices that can convert chemical energy into electrical energy, or vice versa.
    • They can produce an electric current through chemical reactions, or they can use electrical energy to facilitate chemical reactions.
  • Electrochemical cells, like voltaic or galvanic cells, operate via redox reactions wherein electrons are liberated during oxidation and utilized during reduction.
    • A standard cell comprises two sections accommodating metal electrodes immersed in specific electrolytes.
      • The electrodes, namely the anode and the cathode, conduct electricity.
    • The anode, where oxidation occurs, and the cathode, where reduction takes place, form the fundamental components of the cell.
  • Electrons flow from the negatively charged anode to the positively charged cathode through an external circuit, providing power for a variety of uses.
    • Connecting these halves is a wire and a salt bridge, facilitating the movement of ions between them.
  • The energy carried by electrons dictates the source voltage, steering the electron flow within the circuit.
    • In ideal conditions, the source voltage is equal to the terminal voltage, ensuring an efficient power supply.
  • Advancements in cell design and materials, seen in nickel-cadmium, zinc-copper, and modern lithium-ion cells, showcase increased voltages and enhanced efficiency.
• Related Challenges:
  • One of the well-known challenges affecting the efficiency of electrochemical cells is corrosion. For instance, in environments with high humidity, electrodes can gather water droplets.
    • If the atmospheric carbon dioxide levels are elevated, the combination of water and gas leads to the formation of carbonic acid, causing corrosion on the electrode surfaces.
  • Another issue arises from galvanic corrosion, where one of the electrodes within a cell deteriorates faster in the electrolyte due to its higher reactivity.
    • For instance, in a carbon-zinc battery, the zinc electrode erodes more rapidly during the battery's usage.