New energy vehicle charging pile cable: magnesium hydroxide flame retardant solution solves high temperature pain points

Today, as new energy vehicle fast charging technology moves towards the 800V high-voltage platform, the high temperature resistance and flame retardant performance of charging pile cables have become the core pain points that restrict the development of the industry. Under continuous high current conditions, the sheath temperature of traditional cables can reach above 125°C, and ordinary flame retardant systems are prone to thermal degradation, smoke and toxicity release and other problems. The breakthrough in magnesium hydroxide flame retardant technology is redefining the safety boundaries of charging pile cables through high thermal stability design and dynamic flame retardant network construction.

1. Technical breakthrough in high temperature environment

The extreme working conditions of charging pile cables pose dual challenges to materials:

Continuous high temperature tolerance: During 800V high-voltage fast charging, the cable conductor temperature reaches 150-200°C, and the sheath is exposed to an environment above 45°C for a long time;

Instantaneous thermal shock protection: The local temperature exceeds 500°C at the moment of short circuit, and traditional organic flame retardants are prone to decomposition and failure.

The solution of magnesium hydroxide is based on three technological breakthroughs:

Directed regulation of crystal structure: Hexagonal flake crystals synthesized by hydrothermal method, with a thickness of <50nm, a specific surface area increased to 25㎡/g, a thermal decomposition temperature of 420℃, and continuous release of flame retardant performance at high temperature;

Nano-level coating modification: Dual modification of silane coupling agent and sodium perfluorooctanoate, activation index >99%, forming a three-dimensional flame retardant network in the polymer matrix;

Gradient dispersion technology: 3-10μm large particles and submicron powders are compounded in a ratio of 1:3, and the tensile strength of 14MPa is maintained when the filling amount reaches 58%.

According to the actual measurement of a leading cable company, the charging pile cable using this solution passed the IEC 62930 standard test, and the performance attenuation rate was <3% after 3000 hours of wet heat aging at 45℃, and the elongation at break was maintained at 180% at a low temperature of -40℃.

2. Analysis of flame retardant and smoke suppression synergistic technology

1. Dynamic flame retardant mechanism

Heat absorption stage: magnesium hydroxide decomposes and absorbs heat at 300-400℃, reducing the surface temperature of the material, and the heat absorption per gram reaches 1.3kJ;

Gas phase barrier stage: the released water vapor dilutes the oxygen concentration, inhibits the spread of flames, and the smoke density (Dm) is ≤75;

Solid phase coverage stage: the generated magnesium oxide ceramic layer isolates oxygen, and the peak heat release rate (HRR) is reduced by 50%.

2. Breakthrough in smoke and toxicity control

The decomposition products neutralize acidic gases, and the toxicity index (CITG) is <1.0, which reduces emissions by 98% compared with the traditional halogen system;

Compounded with aluminum hydroxide to form a wide temperature range synergistic system, continuously release flame-retardant gases at 200-400℃, and reduce smoke generation by 60%.

The measured data of a new energy vehicle super charging station showed that the visibility of the cable using this solution was maintained at more than 10 meters in the early stage of combustion, which bought critical time for personnel evacuation.

3. Deep coupling of materials and processes

1. Innovation of insulation layer

Cross-linked polyethylene matrix: Using radiation cross-linking technology, the temperature resistance level is increased from 90℃ to 125℃, and the heat deformation temperature reaches 170℃;

Polyarylate resin reinforcement: 20μm polyarylate layer is embedded in glass fiber mesh, dielectric strength>35kV/mm, partial discharge <5pC.

2. Sheath structure optimization

Four-layer co-extrusion process: outer layer magnesium hydroxide/silicone rubber composite sheath, inner layer aerogel insulation layer, and silver-plated copper wire braided shielding layer embedded in the middle;

Cross-shaped plastic skeleton design, compressive strength increased by 50%, dynamic bending life exceeded 100,000 times.

The application of a charging pile project in Jiangsu shows that the insulation resistance retention rate of the cable is>99% in the temperature difference cycle test from -40℃ to 150℃, and the charging loss is reduced by 18%.

IV. Engineering application breakthrough

1. Extreme environment verification

South China Sea salt spray environment test: After 3000 hours of salt spray, the surface is not corroded, and the insulation resistance is greater than 5000MΩ·km;

Gobi Desert wind and sand test: After 200 hours of impact with quartz sand carried by level 8 strong wind, the sheath wear thickness is less than 0.2mm.

2. Intelligent safety protection

Embedded NTC thermistor chip, real-time monitoring of cable temperature, 0.1 second circuit cut-off when overloaded;

Self-repairing sheath technology: 2mm cracks achieve 85% self-healing in an 80℃ environment, and the material life is extended by 30%.

A charging pile cable project of a European car company shows that this solution reduces the weight of the charging gun cable by 25%, and the number of 30-minute fast charging cycles exceeds 15,000 times.

V. The Art of Balancing Cost and Performance

1. Raw Material Cost Reduction Strategy

Using natural brucite instead of chemical synthetic raw materials, the production cost is reduced by 40%, and the D97 particle size is controlled at 5.29μm;

Supercritical CO₂ cleaning and recycling technology for scraps saves more than 10 million yuan in raw material costs annually.

2. Process efficiency improvement path

Using wet ball milling ultrasonic assisted dispersion, the solid content of the slurry is increased to 70%, and the extrusion speed is increased from 30m/min to 45m/min;

Low-temperature dynamic shearing process, the processing temperature is reduced from 220℃ to 180℃, and the energy consumption is reduced by 22%.

Data from a 10,000-ton production line show that this solution reduces the comprehensive cost of cable materials by 18%, and the oxygen index is stabilized at more than 38%.

The magnesium hydroxide flame retardant solution is reshaping the technical paradigm of charging cables with the deep integration of material science and process engineering. From the directional regulation of nanocrystals to the self-healing function of smart sheaths, this flame retardant revolution not only solves the pain point of high temperature, but also promotes the iteration of new energy infrastructure towards high safety and intelligence. In the wave of carbon neutrality and electrification transformation, companies that master core technologies have occupied the high value position in the charging ecosystem chain.