Functional MXene‐Based Materials for Next‐Generation Rechargeable Batteries

Abstract

fuels), such as excessively high temperatures, heavy downpours, severe floods, and droughts. As a response to the climate change, a global coalition for carbon neutrality is committed to be built by 2050 to maintain the sustainability of the global development. An imminent transition of the energy structure from traditional fossil fuels to the renewable energy sources, such as wind, solar, and tide is of great urgency. Due to the intermittent nature of these resources, energy-storage devices, especially the electrochemical energy-storage technologies, are of great significance in ensuring the stability and quality of the energy output. Lithium-ion batteries (LIBs) have been dominating the energy-storage market since its first commercialization in the 1990s. [1] They are currently widely applied in consumable electronics, electric vehicles, and grid-scale energy storage. [2] Yet more concerns have been raised regarding the scarcity and price of the lithium resources in recent years. Therefore, alternative battery technologies based on other metal ions beyond Li ions have been extensively explored. [3] However, finding suitable electrode materials for these batteries to achieve comparative performance to the LIBs remains a challenging task since the charge-carrier metal ions possess much larger ionic radius and stronger interaction with the host materials owing to their multivalent nature. MXenesare seen as an exceptional candidate to reshape the future of energy with their viable surface chemistry, ultrathin 2D structure, and excellent electronic conductivity. The extensive research efforts bring about rapid expansion of the MXene families with enriched functionalities, which significantly boost performance of the existing energy-storage devices. In this review, the strategies that are developed to functionalize the MXene-based materials, including tailoring their microstructure by ions/molecules/polymers-initiated interaction or self-assembly, surface/interface engineering with dopants or functional groups, constructing heterostructures from MXenes with various materials, and transforming them into a series of derivatives inheriting the merits of the MXene precursors are highlighted. Their applications in emerging battery technologies are demonstrated and discussed. With delicate functionalization and structural engineering, MXene-based electrode materials exhibit improved specific capacity and rate capability, and their presence further suppresses and even eliminates dendrite formation on the metal anodes, which lengthens the lifespan of the rechargeable batteries. Meanwhile, MXenes serve as additives for electrolytes, separators, and current collectors. Finally, some future directions worth of exploration to address the remaining challenging issues of MXene-based materials and achieve the nextgeneration high-power and low-cost rechargeable batteries are proposed.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.202204988.

Dual Strategies of Metal Preintercalation and In Situ Electrochemical Oxidization Operating on MXene for Enhancement of Ion/Electron Transfer and Zinc‐Ion Storage Capacity in Aqueous Zinc‐Ion Batteries

“…[29,34] Over the past decade, MXenes have grown into key versatile 2D materials that have been widely applied in photodetectors, [35] pollutant degradation, [36] sensors, [37] and energy storage and conversion. [38][39][40] Equipped with nanolaminate microstructure, superior conductivity, and adequate surface chemistry, [41] MXenes provide a great opportunity for fabrication of highperformance ZIBs. As a member of MXene families, V 2 CT x possesses an accordion-like 2D layered structure and numerous ordered nanochannels, which would be beneficial to electron transport and could provide adequate active sites for the insertion/extraction of Zn 2+ ions.…”

Organics‐MXene Composites as Electrode Materials for Energy Storage

“…There have been a number of excellent review papers to systematically address this topic, i. e., MXene-based materials for electrochemical energy storage. [27,30,32] This paper will not repeat it. Similar to supercapacitors, the insertion of organic molecules not only expands the interlayer spacing of MXene nanosheets, but also enhances the electrical conductivity of organic materials as well as ion transport kinetics, which significantly improve the electrochemical performances of organics/MXene composites.…”

“…), large and controllable layer spacing (up to about 1.7 nm) and high real density (4 g cm À 3 ). [16][17][18][19] It is widely used in gas sensing, [20,21] water purification, [22] ion adsorption, [23] catalysis, [24] electromagnetic interference shielding, [25,26] energy storage [27] and other fields. [28] Due to its good electrical conductivity, surface multifunctional groups and large layer spacing, Ti 3 C 2 T x offers an ideal substrate to combine with other materials, such as inorganic sulfides, transition metal oxide electrode materials, carbon materials, etc., forming Ti 3 C 2 T x -based composite materialsl.…”

Developing a MXene quantum dot-based separator for Li–S batteries

“…22,23 As a large class of new 2D transition metal carbides and carbonitrides, MXene is also widely used in energy-storage applications in relation to its high conductivity. [24][25][26] However, the limited polysulde adsorption sites on its surface will be embedded because of its selfassembly stacking characteristics. 27 The quantization of MXene cannot only avoid stacking, but also the quantum size effect can expose more active sites and improve the chemical adsorption and catalytic conversion ability for polysuldes.…”