What kind of insulation material is needed for power batteries？

Insulation material is a material that is non-conductive under allowable voltage. The electrical resistivity of insulation material is very high, and it is non-conductive or conductive to very little under the action of DC voltage.

The primary function of insulation materials is to isolate charged conductors with different potentials in electrical equipment, allowing current to flow along a particular path. They can also serve as mechanical support and fixation, arc extinguishing, heat dissipation, energy storage, moisture-proof, mold-proof, or to improve the potential distribution of the electric field and protect conductors.

Upgrading batteries in insulation, lightweight, and other directions will bring new opportunities to insulation materials. Downstream application areas continue to expand, and new fields are expected to increase. From the perspective of the industrial chain, upstream raw materials include organic compounds, high molecular weight polymers, and inorganic substances. Downstream materials can be used in the traditional power industry and the automotive, new energy, and 5G communication sectors. In the context of carbon neutrality, demand is expected to continue to increase.

Insulation materials are significant in ensuring electrical products' long-term safe and reliable operation. To prevent accidents caused by damage to the insulation performance of insulation materials, it is necessary to ensure that the insulation materials meet the performance indicators specified in national standards. There are many performance indicators of insulation materials, and the characteristics of various insulation materials are also different. The leading performance indicators of commonly used insulation materials include breakdown strength, heat resistance, insulation resistance, and mechanical strength.

According to the product form, insulation materials can be divided into three categories.

• Gas insulation material: a gas that can maintain insulation between electrodes with potential differences. Gas insulation can self-recover after damage, with advantages such as stable capacitance, minimal dielectric loss, nonflammability, nonexplosion, good chemical stability, nonaging, and low cost. Standard gas insulation materials can be divided into natural gas insulation materials (air, nitrogen, hydrogen, carbon dioxide, etc.) and synthetic gas insulation materials (sulfur hexafluoride, etc.).
• Liquid insulation material, also known as insulating oil, is a liquid that isolates conductive materials with different potentials. They are mainly replacing gas and filling the gaps inside or between solid materials to improve their dielectric properties and the equipment's heat dissipation capacity. Liquid insulation materials can be divided into three categories: mineral insulation oil, synthetic insulation oil, and vegetable oil. The most commonly used oil in engineering is still mineral oil.
• Solid insulation material: Besides isolating conductive materials with different potentials, it is generally required to have a supporting effect. Many types of solid insulation materials can be divided into two categories: inorganic (high-temperature resistance, not easy to age but poor processing performance) and organic (flexible, easy to process but easy to age and poor heat resistance). Inorganic solid insulation materials mainly include mica, porcelain, glass, and other products. Organic solid insulation materials are divided into natural organic materials (natural rubber, silk, cotton cloth, etc.) and synthetic organic materials (insulation paint, plastic, and synthetic rubber).