A mandrel is a cylindrical object used as a core around which material can be wrapped. In the case of lithium-ion batteries, the mandrel is used to form the cathode and anode electrodes of the battery.
How is the mandrel used in the manufacturing process?
The mandrel is used to create a consistent and uniform shape for the cathode and anode electrodes. The process begins with a slurry, which is a mixture of the active electrode material, a conductive additive, and a binder. This slurry is then coated on the surface of the mandrel and dried to form a thin layer.
The mandrel is then rotated, and the slurry is coated onto the surface again. This process is repeated several times until the desired thickness is achieved. The mandrel is then heated to remove any remaining solvent and bind the electrode materials together.
Once the electrodes are complete, they are removed from the mandrel, and the separator and electrolyte are added to form the final battery.
Why is the mandrel important?
The mandrel plays a critical role in the construction of lithium-ion batteries. The consistent and uniform shape of the electrodes is essential for the performance and safety of the battery.
If the electrodes are not uniform, it can lead to uneven distribution of the active material, resulting in lower energy density and reduced battery life. In addition, non-uniform electrodes can create hot spots within the battery, which can lead to thermal runaway.
The mandrel also allows for the production of different electrode shapes, which can be used to optimize the performance of the battery.