Electrochemical Cells & Electrolytic Cells
What Are Electrochemical Cells?
An electrochemical cell is a system that converts:
• Chemical energy → Electrical energy (spontaneous reaction)
OR
• Electrical energy → Chemical energy (non-spontaneous reaction)
All electrochemical cells involve:
• Redox reactions
• Electron transfer
• Anode and cathode
• An external circuit
Galvanic (Voltaic) Cells
Definition
A galvanic cell (also called a voltaic cell) produces electricity from a spontaneous
redox reaction.
Electrons flow naturally from the more reactive metal to the less reactive metal.
Example: The Daniell cell
, Components:
• Zinc electrode in Zn²⁺ solution
• Copper electrode in Cu²⁺ solution
• Salt bridge
• External wire
Half Equations:
Anode (oxidation): 𝑍𝑛(𝑠) → 𝑍𝑛2+ (𝑎𝑞) + 2𝑒 −
Cathode (reduction): 𝐶𝑢2+ (𝑎𝑞) + 2𝑒 − → 𝐶𝑢(𝑠)
Key Features
Feature Galvanic Cell
Energy conversion Chemical → Electrical
Reaction type Spontaneous
Anode Oxidation
Cathode Reduction
Electron flow Anode → Cathode
Cell potential Positive
Applications of Galvanic Cells
Batteries
• Dry cells
• Lithium-ion batteries
• Car batteries
Example:
Lithium-ion battery (phones, laptops)
Corrosion & Protection
• Understanding rusting
• Sacrificial protection (e.g., zinc protecting iron)
Electrolytic Cells
Definition
What Are Electrochemical Cells?
An electrochemical cell is a system that converts:
• Chemical energy → Electrical energy (spontaneous reaction)
OR
• Electrical energy → Chemical energy (non-spontaneous reaction)
All electrochemical cells involve:
• Redox reactions
• Electron transfer
• Anode and cathode
• An external circuit
Galvanic (Voltaic) Cells
Definition
A galvanic cell (also called a voltaic cell) produces electricity from a spontaneous
redox reaction.
Electrons flow naturally from the more reactive metal to the less reactive metal.
Example: The Daniell cell
, Components:
• Zinc electrode in Zn²⁺ solution
• Copper electrode in Cu²⁺ solution
• Salt bridge
• External wire
Half Equations:
Anode (oxidation): 𝑍𝑛(𝑠) → 𝑍𝑛2+ (𝑎𝑞) + 2𝑒 −
Cathode (reduction): 𝐶𝑢2+ (𝑎𝑞) + 2𝑒 − → 𝐶𝑢(𝑠)
Key Features
Feature Galvanic Cell
Energy conversion Chemical → Electrical
Reaction type Spontaneous
Anode Oxidation
Cathode Reduction
Electron flow Anode → Cathode
Cell potential Positive
Applications of Galvanic Cells
Batteries
• Dry cells
• Lithium-ion batteries
• Car batteries
Example:
Lithium-ion battery (phones, laptops)
Corrosion & Protection
• Understanding rusting
• Sacrificial protection (e.g., zinc protecting iron)
Electrolytic Cells
Definition
