Ceramic Seal Ring: The "Security Guards" of Power Batteries

With the rapid rise of the new energy vehicle industry, the application of ceramic materials in this sector has increasingly highlighted its importance. Today, we will focus on a key component in electric vehicle batteries—the ceramic seal ring.

The reason why the ceramic seal ring plays an indispensable role in power batteries is due to its unique physical properties and intricate structural design. The following is an in-depth analysis of its sealing principles:

Selected Materials

The ceramic seal ring is made of high-purity, high-hardness ceramic materials such as alumina and silicon nitride. These materials not only have a low thermal expansion coefficient, but are also wear-resistant and chemically stable, allowing them to function reliably in harsh environments such as high temperatures, high pressures, and corrosive media.

Sealing Mechanism

The ceramic seal ring is primarily used for static sealing. Its inner and outer rings are respectively installed on both sides of the sealing surface, forming a sealing loop. When the medium pressure acts on the sealing surface, the ceramic seal ring undergoes elastic deformation under the pressure, closely adhering to the sealing surface to achieve sealing. The high hardness of the ceramic ensures that the sealing ring can withstand the strong pressure of the medium, ensuring the sealing effect.

Excellent Performance

The ceramic seal ring ensures the flatness of the sealing surface with its high hardness, effectively resisting wear and scratches. Meanwhile, its low thermal expansion coefficient reduces the impact of temperature changes on the sealing performance. Additionally, ceramic materials have excellent corrosion resistance, capable of withstanding corrosive media such as acids and bases.

Although ceramics have significant advantages as an electrically insulating material between metals, achieving a tight, hermetic connection between metal and ceramic is challenging. However, thanks to the maturity of ceramic-metal connection technology, metalizing ceramic surfaces has become possible. This involves melting metal to wet the ceramic surface, causing interfacial reactions or element diffusion to metalize the ceramic surface. Combined with brazing technology, the metal pole and metal sealing cap can be tightly welded, ensuring the reliability of the seal.

Currently, plastic or glass sealing rings are prone to failure under high pressure conditions, affecting battery life and failing to meet the requirements of special batteries. In contrast, the properties of ceramic materials make it become an ideal choice due to their excellent acid and alkali resistance, corrosion resistance, and high-temperature performance. Nowadays, the ceramic seal ring is being increasingly utilized in the power lithium battery industry.