Electrodeposition and electroplating are two commonly used electrochemical surface treatment methods, and there are some differences in their working principles:

How it works:
Electrodeposition: Electrodeposition is the process by which metal ions are reduced from an electrolyte solution and deposited onto the surface of the workpiece to form a metal coating. In electrodeposition, the plated workpiece acts as a cathode and is connected to the negative end of the power supply, while the anode is usually an electrode in an electrolyte solution of the same metal.

Electroplating: Electroplating is the process of providing protection, decoration, or other special properties by depositing a metal coating on the surface of a workpiece. In electroplating, the plated workpiece is usually used as an anode, connected to the positive electrode of the power supply, while the cathode is the source of metal ions, which can be a metal block or other metal electrodes in the electrolyte solution.

The working principle of electrodeposition and electroplating is different

Electrolyte solution:
Electrodeposition: Electrodeposition usually uses an electrolyte solution containing metal ions, which are reduced and deposited on the surface of the workpiece during electrolysis. The concentration and composition of metal ions in the electrolyte solution can affect the properties of the final deposition layer.

Electroplating: The electrolyte solution of electroplating usually contains ions of the metal to be coated as well as other additives, such as inhibitors, enhancers, etc. These additives can adjust the properties and appearance of the coatings and provide better coating quality.

Purpose of Application:
Electrodeposition: Electrodeposition is mainly used for the repair and modification of metal surface, which can repair the damaged metal surface and improve its appearance and performance through electrodeposition.

Electroplating: Electroplating is mainly used to provide protective coating, decorative coating or special performance coating. Electroplating can improve the corrosion resistance, wear resistance, electrical conductivity and other properties of metals, and can change the appearance of metals.

In general, both electrodeposition and electroplating are methods of using electric current and metal ions in electrolyte solution to form metal coating on the surface of workpiece, but they have some differences in working principle and application purpose. Electrodeposition is more focused on repair and modification, while electroplating is more focused on providing protection and improving performance.