The plastic conductive bipolar plate is generally composed of polyethylene (PE) and polypropylene (PP) or other high molecular polymers and conductive carbon materials including graphite, carbon black and carbon fiber. After mixing, drying, calendering, forming process, plastic bipolar plate materials have both conductivity and good mechanical properties. They are widely used in the production and manufacturing of all vanadium, iron chromium, zinc bromide and other flow batteries. The conductivity of the composite materials is limited by the conductivity of the filler materials and the compatibility of the polymer and conductive filler. In order to ensure the overall tightness of the battery stack and reduce the contact resistance, great pressure is needed when assemble the stack, so the mechanical properties of the resin material are also very important for the plastic conductive bipolar plate.

Application of plastic conductive bipolar plates in VRFB

Vanadium battery provides an ideal solution for large-scale energy storage of new energy such as solar energy and wind energy, and also involves in power grid, communication base station, UPS, automobile charging and other applications. Since the electrolyte of the positive and negative electrodes are both vanadium ion solution, different from other flow batteries, cross contamination of electrolytes will be avoided. Generally, the reaction of vanadium ion on the electrode surface doesn’t require a catalyst. As one of the important components for vanadium batteries, conductive plastic bipolar plates can collect and conduct the current generated by electrochemical reaction and separate the positive and negative electrolyte. Comparing to metal and graphite plates, plastic bipolar plates have the properties of low cost, good toughness and corrosion resistance. Through adjusting the amount of conductive filler and processing technology, high-quality conductive bipolar plate (BPs) materials with low resistivity and high mechanical properties can be made.

Application of conductive plastic bipolar plate in ICRFB

Iron-chromium redox flow battery(ICRFB) is an important branch of energy storage batteries. It’s broadly applied in the field of new energy storage such as power generation and grid connection, peak load shifting. Due to the abundant resources of iron and chromium , the cost of electrolyte is lower than that of all vanadium redox battery. In addition, we know that vanadium possesses toxicity, and iron chromium batteries are relatively friendly to the environment. In 2017, the State Power Investment Corporation developed the iron chromium flow battery named “Ronghe No.1”, which marks that the Fe-Cr redox flow battery has entered the era of industrialization and standardization. As one of the key materials of battery stack, the conductive plastic bipolar plate has also got the opportunity of development. XNHY has developed a new generation of plastic conductive bipolar plate materials with good conductivity and toughness through the optimization of raw material ratio and structural design, and realize the supply of carbon plastic composite bipolar plates in scale.

Application of plastic conductive bipolar plate in ZNBR

Zinc bromine flow battery(ZNBR) has made rapid development in the United States, Japan, Australia and other countries. With Zn-Br battery as the core, various small and medium-sized photovoltaic energy storage and power supply systems have been developed in sparsely populated areas. In recent years, large-scale energy storage field has attracted more and more attention in China. Compared to other redox flow batteries, zinc has a broad commercial prospect and potential due to its advantages of high energy density and low cost. The conductive plastic bipolar plate is the key component for joining zinc bromine flow battery stacks. It’s made of conductive materials such as polymer resin and graphite through special processes. Free of heavy metals and can be recycled. It possesses good mechanical properties, electrical conductivity, thermal stability and corrosion resistance. The second-generation of plastic conductive bipolar plates also adds a design of flow channel, so that the electrolyte can flow in the bipolar plate, and the structure is more simple and stable.