How to select appropriate materials for charging piles so that charging piles can still provide safe and convenient charging services for new energy vehicles in the long-term exposed outdoor environment?

Much can be explored following the rise ofnew energy vehicles, for instance, charging stations for electric vehicles(EV). These chargers must withstand different weather conditions while offeringsafe and reliable charging service for the cars.

From 2015 to 2020, 4.8m charging piles and 12,000 charging stations will be built across the country, according to the guidelines for the development of ev charging infrastructure (2015-2020) issued by the national development and reform commission.

From 2015 to 2020, 3,848 bus charging stations, 2,462 taxi charging stations, 2,438 special vehicle charging stations such as sanitation and logistics, 4.3 million special charging piles for official vehicles and private cars, 2,397 urban public charging stations, 500,000 decentralized public charging piles and 842 intercity quick charging stations are needed.

Industry figures estimate this will unlock the potential of the rmb90bn charging pile market.

The huge market potential has attracted many enterprises to enter the bureau. China's charging pile industry has entered a period of rapid growth, and the number of enterprises has doubled, but there are many hidden dangers behind the rapidly expanding market.

However, no matter how the charging pile industry develops in the future, how its power supply system and power grid change, materials are always the key to its development!

Because charging piles are often exposed to outdoor environment, the outdoor environment has high requirements on the quality of shell material outside charging piles. In addition, there is no unified industry standard in the market, resulting in poor product matching and uneven performance, resulting in great waste and hidden trouble in installation.

So how to choose the right material for the charging pile?

There are six parts of charging pile shell that can be used in plastics, including charging pile shell, charging pile plug, charging pile socket, charging gun shell, circuit breaker, contactor and power module shell. The shell material of different parts has corresponding material selection requirements, which should meet the performance requirements as well as economic and safety requirements.

No matter which kind of plastics you choose, they are best through ROHS certification and UL yellow card certification, to meet the requirements of high temperature resistance, insulation, easy processing, easy coloring, shock resistance and so on.

Shell: flame retardant, weather resistance and low temperature resistance

Among them, the charging pile housing and charging gun shell can be made of PC or PC/ABS with good properties of flame retardant, weather resistance and low temperature resistance.

PC material of hot wire light-off temperature GWIT ≧ 750 ℃ hot wire, CTI (tracking index) ≦ 250 v, halogen free flame retardant UL94-V0@0.8mm, strong resistance to low temperature toughness (- 40 ℃ can keep good impact properties).

PC/ABS material should have the following characteristics: CTI (tracking index) ≧ 250 v, high and low temperature performance is good (to 40 ℃ to 60 ℃).

Plug and socket: good insulation effect

The charging pile plug and socket shell can be made of PET or PA66 modified materials with good insulation effect and moderate strength.

PET materials good dimensional stability, such as flame retardant UL94-V0@0.8mm mm5VA (1.6), high temperature resistance RTI value is: 155 ℃;

Hot wire of PA66 GWIT flame temperature of 800 ℃ (0.4 mm), CTI (≧ 600 v tracking index), flame retardant grade UL94 - where V0 @ 0.4 mm.

Power module: high strength

The shell of charging pile power module and internal circuit control system can be modified by nylon series of materials with good insulation effect and high strength.

The material selection of the power module shell should be flame retardant UL94-V0@0.8mm. The halogen-free flame retardant of the internal circuit control system can reach UL94-V0@0.8mm. The electrical performance should meet CTI wufu600v, and the yellow resistance is better.

Charging pile material selection example

Costibicane series plastic alloy.

One of the first materials technology enterprises to enter the field of charging piles, coxtron polymer (China) co., ltd. launched the application of bibenlan (PC/ABS) series of plastic alloy and model clone PC series products in charging pile shell at its CHINAPLAS 2016 booth.

The flame retardant PC of coxtron is not only on the charging pile, but also on the power battery, providing a material and structural design solution for packaging.

Compared with metal, the use of lightweight polycarbonate material can effectively improve the energy density of the battery module, and the solid support simplifies the structural design and reduces the cost of battery assembly while protecting the cell.

In addition, the low water absorption property of polycarbonate can maintain good long-term shape size stability without deformation effect.

Coxtron offers a variety of packaging design solutions to effectively control battery charge-discharge thermal energy and improve battery life.

In addition to coxtron, domestic enterprises such as goldilocks technology and jucerone have also launched corresponding material solutions for charging piles.

Gather the acetate modified through the use of advanced technology on PC and PC/ABS material to optimize performance and successful development of materials such as PC - 2370 - T, FRPC/ABS 3370, can meet the 2016 new charging pile on the implementation of the new standard of the electric conduction charging system, part 1: general requirements ", the electric conduction charging with connection part 1: general requirements ", the electric conduction charging device with connection part 2: ac charging interface ", the electric conduction charging with connection part 3: dc charging interface ".

Quality stability is urgently needed

Although the technical threshold of plastic material selection is not high for each part of the charging pile, the special use environment of the charging pile requires a comprehensive and relatively balanced performance of these kinds of performances, which is of high difficulty. In addition, the stability of the product is also a problem.

Stable quality may be a problem that material suppliers need to jointly solve and continuously supervise in the future.