The development trend and technological barriers of wireless charging

1、 Development Trends

1. High frequency and high efficiency

-High frequency materials and devices: The popularity of GaN (gallium nitride) and SiC (silicon carbide) devices has driven the development of wireless charging frequencies towards the MHz level, improving power density and efficiency. For example, the demand for 800V high-voltage platforms in new energy vehicles has spurred the development of 50kW+high-power winding equipment.

-High frequency magnetic core materials: Nickel zinc ferrite (Ni Zn) and nanocrystalline materials (such as TDK HF90 series) have become mainstream, reducing losses by 30% and suitable for high-frequency scenarios.

2. Dynamic coil technology and improvement of positional freedom

-Active Alignment Technology (APP): Qi2.1 standard introduces mobile coil technology, and the car charger can automatically detect the position of the phone and adjust the coil alignment, solving the problem of unstable charging caused by driving vibration. Panasonic and Toyota are collaborating to promote the commercialization of this technology, and Tesla and other car companies plan to follow suit.

-Multi coil array design: supports simultaneous charging of multiple devices, with an offset tolerance of ± 20mm, compatible with devices of different sizes.

3. Diversified application scenarios

-New energy vehicles: The demand for wireless charging in vehicles has surged, and it is expected that 150-200 winding devices will be required for every 10000 new energy vehicles, promoting the development of coils towards high power (50kW+) and high tension (3000N level).

-Industry and Medical: Emerging scenarios such as wind turbines and medical micro coils require coils to withstand extreme environments (such as -40 ℃~125 ℃) and ultra-thin designs (below 0.1mm).

4. Standardization and ecological integration

-Qi2 standard popularization: Supports magnetic alignment (MPP) and compatibility with non-magnetic devices (APP), with over 1.5 billion Qi2 devices worldwide by 2025, accelerating adaptation in the Android camp.

-Industrial chain collaboration: Terminal manufacturers such as Huawei and Xiaomi are promoting coil miniaturization and high power, driving winding equipment enterprises (such as Tanaka Precision Machinery) to transform towards vertical integration (winding module integration).

2、 Technical barriers

1. Material performance limitations

-High frequency losses and thermal management: At MHz operating frequencies, traditional ferrites experience a significant increase in losses, requiring nanocrystalline materials or composite magnetic materials (such as Ferroxcube 3F45), but with high costs and complex processes.

-Flexibility and temperature resistance: Automotive and wearable devices require coils to be bendable and resistant to high temperatures (>125 ℃), with flexible ferrites such as Vishay Flexield ™） The mass production yield is only 80% -90%.

2. Manufacturing accuracy and process complexity

-Winding accuracy: Consumer electronics coils require a precision of ± 0.01mm, relying on magnetic levitation spindles and AI tension control technology. Domestic equipment still lags behind Japanese companies (such as Nippon Paint) in the high-end market.

-Multi layer winding and integration: The flat wire motor for new energy vehicles requires 60mm ² thick wire diameter multi-layer winding, and the equipment needs to be compatible with multi station synchronous operation, with a high technical threshold.

3. Compatibility and standardization challenges

-Multi protocol adaptation: Qi, AirFuel, and private protocols (such as Huawei SuperCharge) coexist, and the coil needs to consider different frequencies (110kHz-6.78MHz) and powers (5W-50W), doubling the design complexity.

-Vehicle regulation certification: AEC-Q200 certification requires coils to operate stably in extreme environments such as vibration and humidity, with long testing cycles and high costs.

4. Cost and supply chain risks

-Dependence on rare earth materials: Fluctuations in the prices of magnetic materials such as Ru iron boron affect coil costs, and alternative solutions need to be developed (such as iron powder cores).

-High end equipment import dependence: 85% of the market share of high-power winding equipment above 50kW is monopolized by Japanese companies, and the process of domestic substitution is slow.

3、 Future breakthrough direction

1. Material innovation: Develop low-cost nanocrystalline magnetic cores and graphene composite heat dissipation materials to reduce high-frequency losses.

2. Intelligent manufacturing: Integrating AI visual inspection and adaptive winding algorithms to improve yield to over 99.5%.

3. Technical breakthroughs at the automotive level: Optimize coil packaging processes (such as epoxy resin encapsulation), obtain AEC-Q200 certification, and adapt to 800V high-voltage platforms.

4. Global standard collaboration: Promote the integration of Qi2 with agreements in the automotive and home appliance industries, and reduce the cost of adapting to multiple scenarios.

summarize

Wireless charging coils are developing towards high frequency efficiency, dynamic intelligence, and multi scenario compatibility, but they need to overcome multiple barriers in materials, processes, and standardization. Enterprises need to focus on high-precision manufacturing, automotive grade technology, and industrial chain integration to cope with the competition and opportunities in the billion dollar market after 2025.