Redox flow batteries (RFBs) are one of the most promising techniques to store and convert green and renewable energy, benefiting from their advantages of high safety, flexible design and long lifespan. Membranes with fast and selective ions transport are required for the advances of RFBs. Remarkably, two-dimensional (2D) materials with high mechanical and chemical stability, strict size exclusion and abundantly modifiable functional groups, have attracted extensive attentions in the applications of energy fields. Herein, the improvements and perspectives of 2D materials working for ionic transportation and sieving in RFBs membranes are presented. The characteristics of various materials and their advantages and disadvantages in the applications of RFBs membranes particularly are focused. This review is expected to provide a guidance for the design of membranes based on 2D materials for RFBs.

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With the rapid development of China’s electric power industry, the high-voltage and long-distance direct current (DC) transmission effectively solved the problem of uneven power distribution. When the high voltage direct current transmission is in unipolar operation or bipolar asymmetric operation, part of the DC current will flow into the transformer winding through the grounded neutral point, which will cause the DC bias problem. This article used CDEGS software for modeling, and introduced the process of CDEGS software for DC bias simulation modeling. In this paper, the DC bias model of regional power grid is first established, based on the Zhejiang power grid topology and the test soil resistivity date. Then the DC bias currents of the transformers are calculated, and finally the corresponding treatment measures are proposed. According to the governance measures, this article adjusted the simulation model. The calculation results show that the treatment measures have good effects, which can provide an important reference for the future treatment of transformer DC bias.