Lithium-ion batteries Sodium-ion batteries a b s t r a c t Molybdenum and tungsten chalcogenides have attracted tremendous attention in energy storage and conversion due to their outstanding physicochemical and electrochemical properties. There are intensive studies on molybdenum and tungsten chalcogenides for energy storage and conversion, however, there is no systematic review on the applications of WS 2 , MoSe 2 and WSe 2 as anode materials for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), except MoS 2 . Considering the importance of these contents, it is extremely necessary to overview the recent development of novel layered WS 2 , MoSe 2 and WSe 2 beyond MoS 2 in energy storage. Here, we will systematically overview the recent progress of WS 2 , MoSe 2 and WSe 2 as anode materials in LIBs and SIBs. This review will also discuss the opportunities, and perspectives of these materials in the energy storage fields.

Carbon is a simple, stable and popular element with many allotropes. The carbon family members include carbon dots, carbon nanotubes, carbon fibers, graphene, graphite, graphdiyne and hard carbon, etc. They can be divided into different dimensions, and their structures can be open and porous. Moreover, it is very interesting to dope them with other elements (metal or non‐metal) or hybridize them with other materials to form composites. The elemental and structural characteristics offer us to explore their applications in energy, environment, bioscience, medicine, electronics and others. Among them, energy storage and conversion are extremely attractive, as advances in this area may improve our life quality and environment. Some energy devices will be included herein, such as lithium‐ion batteries, lithium sulfur batteries, sodium‐ion batteries, potassium‐ion batteries, dual ion batteries, electrochemical capacitors, and others. Additionally, carbon‐based electrocatalysts are also studied in hydrogen evolution reaction and carbon dioxide reduction reaction. However, there are still many challenges in the design and preparation of electrode and electrocatalytic materials. The research related to carbon materials for energy storage and conversion is extremely active, and this has motivated us to contribute with a roadmap on ‘Carbon Materials in Energy Storage and Conversion’.

The demand for grid-scale energy storage systems has rapidly grown over recent years, to meet the requirements of structural innovation within the energy industry. Due to their inexpensive manufacturing and operating costs, and the similar electrochemical mechanism with the well-established lithium-ion batteries (LIBs), sodium ion batteries (SIBs) have been considered as an attractive candidate for grid-scale energy storage systems. A variety of cobalt-based cathode and anode materials, including cobalt oxides, cobalt chalcogenide and layered sodium cobaltate, have been synthesized and evaluated for sodium storage within the academic literature. In this article, we present a comprehensive review of the recent progress with cobalt-based electrodes (both as an anode and cathode material) used in SIBs. In detail, the electrochemical mechanisms, advantages and disadvantages, the relationship between crystalline structure and electrochemical performance and strategies to enhance the overall electrochemical performance of cobalt-based cathode and anode materials are discussed. Up to now, some cathode materials have already reached a high energy density, which is comparable to commercial LIBs. Furthermore, some cobalt-based materials can maintain a high Coulombic efficiency of over 99% with high reversible capacity during long cycling life. These encouraging results, allow such cobalt-based electrode materials to be a potential solution for grid-scale SIB systems.

No abstract

No abstract