XiaoLong Xu

The applications of zeolitic imidazolate framework-8 in electrical energy storage devices: a review

In order to meet the requirement of electric vehicles (EVs), hybrid electric vehicles (HEVs) and smart grids, effective energy storage devices will become imperative in the future energy technologies. However, it is necessary to further improve the energy density, rate performance and cycle performance of the energy storage devices. Zeolitic imidazolate framework-8 (ZIF-8) is a kind of porous materials that has attracted enormous attention due to its high surface areas, controllable structures and tunable pore sizes. Besides the applications in gas storage and separation, catalysis, sensor, and drug delivery, ZIF-8 is receiving increasing research interest in the field of electrochemical energy storage due to the advantage of synthetic method, such as simplicity and safety. By focusing on recent advances, we summarize the applications of ZIF-8 in electrical energy storage devices, such as rechargeable batteries and supercapacitors. We also list the current problems in applications and give the future study direction.

Review on the roles of carbon materials in lead-carbon batteries

Lead-acid battery (LAB) has been in widespread use for many years due to its mature technology, abound raw materials, low cost, high safety, and high efficiency of recycling. However, the irreversible sulfation in the negative electrode becomes one of the key issues for its further development and application. Lead-carbon battery (LCB) is evolved from LAB by adding different kinds of carbon materials in the negative electrode, and it has effectively suppressed the problem of negative irreversible sulfation of traditional LAB. Different carbon materials play different roles in LCB, including construction of conductive network, double-layer capacitance storage effect, formation of porous structure and steric effect. Moreover, research on composite material additives (such as Pb-C composite materials and polymer-C composite materials) and Pb-C composite electrode have become a research focus in the past few years; it has been another effective way to improve the performance of the negative electrode. On the other hand, due to the relatively low overpotential of carbon materials, the hydrogen evolution reaction (HER) will be aggravated in LCB, which affects its electrochemical performance. It is necessary to modify carbon additives or add other additives to inhibit the HER. This paper will attempt to summarize the roles of carbon additives in the negative electrode made by previous research and illustrate the effect of composite material additives and Pb-C composite electrode on the negative electrode. Moreover, we will also sum up the method for solving the HER by reviewing previous research.