Nano energy: "pillar structure" two-dimensional material effectively improves the performance of Na / Li battery

In recent years, the interest of graphene in the scientific community has gradually expanded to other two-dimensional materials At present, a class of two-dimensional transition metal carbon / nitride mxene has attracted extensive attention Similar to graphene, two-dimensional mxene is derived from three-dimensional Max phase Generally speaking, Max materials have a general structural formula: Mn + 1AXN, where n is equal to 1, 2 or 3, M is generally the early transition metal, a is the main group element, and X is carbon or nitrogen Mxene can be obtained by selectively etching layer a in Max phase Mxene is an ideal electrode material for metal ion batteries (LIBS, sibs, PIBs) due to its unique micro morphology, high theoretical capacity and adjustable layer spacing The preparation of a-ti3c2mnrs (source: nano energy) common ti3c2mxene nano tablets and their derivatives have excellent electrochemical properties, which has become a research hotspot at present It has been found that the reversible capacity of Ti3C2 mxene nano sheet is between 320-410 MAH / g when it is used as LIBS anode material due to its unique multilayer Li adsorption characteristics and low Li atom diffusion barrier, and the magnification performance is due to the graphite electrode When Ti3C2 MNSs is used in supercapacitor, the volume capacitance is about 300-900 f / cm3 Recent theoretical studies and experimental tests show that ti3c2mnss has high power capacity and good long-term cycle stability, which is suitable for the electrode materials of sodium ion batteries (SIBS) and potassium ion batteries (PIBs) The pillared structure of Na + captured by mxene can effectively maintain the stability of the layer spacing, which is conducive to the realization of rapid reversible natriuretic desnatriuretic process However, there are some problems in the traditional Ti3C2 MXene films, such as serious stacking of layers, small layer spacing, low specific capacity and poor cycle performance Therefore, it is urgent to develop new mxene based energy storage materials with stable structure and performance A-ti3c2mnrs appearance characterization (source: nano energy) Wu Zhongshuai team of Dalian Institute of chemistry, Chinese Academy of Sciences developed a new strategy for the shock treatment of ti3c2mxene with KOH solution One step realized the preparation of alkalized ti3c2mxene nanobelts (a-ti3c2mnrs) A-ti3c2 MNRS have large layer spacing (12.5 Å), narrow width (6-22 nm), ultra-thin thickness and open network structure, and have developed ion and electron fast transmission channels, which significantly improve the stability of the electrode structure It was found that a-ti3c2 MNRS can be used as anode materials for high capacity sodium ion batteries (SIBS) and potassium ion batteries (PIBs) When the current density is 20mA / g, the reversible capacity of sibs and PIBs is 168mah / g and 136mah / g respectively; when the current density is increased to 200mA / g, the reversible capacity is 84mah / g and 78mah / g respectively; meanwhile, both sibs and PIBs show good cycle stability, and cycle 5 at high current density of 200mA / g After 00 times, the reversible capacity can still be kept at 50mah / g and 42mah / g respectively, which is better than most of the reported mxene based electrode materials This method is expected to be extended to the construction of other three-dimensional mxene new structures and broaden the application scope of mxene materials Paper link: http://