We developed two-step solution-phase reactions to form hybrid materials of Mn3O4 nanoparticles on reduced graphene oxide (RGO) sheets for lithium ion battery applications. Mn3O4 nanoparticles grown selectively on RGO sheets over free particle growth in solution allowed for the electrically insulating Mn3O4 nanoparticles wired up to a current collector through the underlying conducting graphene network. The Mn3O4 nanoparticles formed on RGO show a high specific capacity up to ~900mAh/g near its theoretical capacity with good rate capability and cycling stability, owing to the intimate interactions between the graphene substrates and the Mn3O4 nanoparticles grown atop. The Mn3O4/RGO hybrid could be a promising candidate material for high-capacity, low-cost, and environmentally friendly anode for lithium ion batteries. Our growth-on-graphene approach should offer a new technique for design and synthesis of battery electrodes based on highly insulating materials.

Mn3O4-Graphene Hybrid as a High Capacity Anode Material for Lithium Ion Batteries

2D MXene-based nanomaterials have attracted tremendous attention because of their unique physical/chemical properties and wide range of applications in energy storage, catalysis, electronics, optoelectronics, and photonics. However, MXenes and their derivatives have many inherent limitations in terms of energy storage applications. In order to further improve their performance for practical application, the nanoengineering of these 2D materials is extensively investigated. In this Review, the latest research and progress on 2D MXene-based nanostructures is introduced and discussed, focusing on their preparation methods, properties, and applications for energy storage such as lithium-ion batteries, sodium-ion batteries, lithium-sulfur batteries, and supercapacitors. Finally, the critical challenges and perspectives required to be addressed for the future development of these 2D MXene-based materials for energy storage applications are presented.

Nanoengineering of 2D MXene-Based Materials for Energy Storage Applications

Synthesis, characterizations, and utilization of oxygen-deficient metal oxides for lithium/sodium-ion batteries and supercapacitors

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'.

2020 Roadmap on Carbon Materials for Energy Storage and Conversion.

Metal selenides for high performance sodium ion batteries

Alkali-metal (Li, Na, K) ion batteries have practically or potentially been widely used as power sources for portable electronic devices and electric vehicles. However, the lack of fast and high-capacity anodes is restricting their development. As a new member of two-dimensional transition metal dichalcogenides, rhenium disulfide (ReS2), with a large interlayer space and weak van der Waals interaction between layers, can enable a large number of intercalation ions to diffuse easily between the layers. In this review, we summarize the recent progress of ReS2 as an electrode for alkali-metal ion batteries, mainly focusing on the synthesis method, structures, the reaction mechanism, and the corresponding electrochemical performance. In addition, the perspective and challenges of ReS2 electrodes are also discussed. This review will provide comprehensive knowledge of ReS2 electrodes and guidelines for exploring more applications in batteries.

Xuan Xie

Papers

ReS2-Based electrode materials for alkali-metal ion batteries

Porous surfur-doped hard carbon for excellent potassium storage

Mesoporous Carbon‐Coated Bismuth Nanorods as Anode for Potassium‐Ion Batteries