Electrolysis

• Molten refers to an ionic compound in liquid state
• Electrolysis reverses the process of galvanic cells by converting electrical energy into chemical energy. It allows for non-spontaneous reactions to occur
• • Reduction occurs at the cathode and is negative.
  • Oxidation occurs at the anode and is positive
• During the electrolysis of an aqueous solution water is present, in some cases as water is either the strongest oxidising or reducing agent it would participate in the reaction.
• • Advantages of a molten solution, is that water is not present, however, the cost of maintaining high temperatures is expensive
  • Advantages of an aqueous solution, is that it is cheaper to operate, but water may interfere with the operation
• Electroplating is when a thin surface of metal is applied over a surface, this occurs during electrolysis
• Faraday's first law of electrolysis states that the mass formed is directly proportional to the electrical charge through the cell
• One mole of electrons contain 96500 coulombs
• High reaction rate:

  • High pressures
  • High temperature
  • High Surface Area
  • Use of catalyst
• High equilibrium yield

  • Increasing the number of reactants
  • Low temperature for exothermic, high temperature for endothermic
  • Removal of products
• Primary cells are used once and is non-recharageable
• Secondary cell are rechargeable and can be used multiple times
• Secondary cell

  • During discharge the cell acts as a galvanic cell, converting chemical energy into electrical energy
  • During recharge the cell acts as an electrolytic cell, converting electrical energy into chemical energy
• Lithium ion batteries is a low density battery with a high energy capacity during recharge at the anode:

  $LiC_6 ->Li^+$$+$$C_6 +$$e^-$

  At the cathode:

  $CoO_2 +$$Li^+$$+$$e^-->LiCoO_2+$$C_6$
• Brown Hydrogen: Derived from fossil fuels

  Grey Hydrogen: Derived from industrial processes

  Blue Hydrogen: Derived from fossil fuel with carbon capture

  Green Hydrogen: Derived using renewable energy
• A polymer electrolyte membrane electrolyser uses a solid electrolyte instead of a solution
• A photoelectricalchemical cell uses energy from the sun to cause excitation of the metals in the electrode