The phase-controlled synthesis of metallic and ambient-stable 2D MX 2 (M is Mo or W; X is S) with 1T octahedral coordination will endow these materials with superior performance compared with their semiconducting 2H coordination counterparts. We report a clean and facile route to prepare 1T-MoS 2 and 1T-WS 2 through hydrothermal processing under high magnetic fields. We reveal that the as-synthesized 1T-MoS 2 and 1T-WS 2 are ambient-stable for more than 1 year. Electrochemical measurements show that 1T-MoS 2 performs much better than 2H-MoS 2 as the anode for sodium ion batteries. These results can provide a clean and facile method to prepare ambientstable 1T-phase MX 2 .

commercial LIBs with graphite-based materials as anode cannot meet the above requirements due to the limitation of graphite itself. It shows a low theoretical capacity of 372 mAh g −1 , [2] rapid capacity decay, and possible safety issues during cycling process. Recently, transition metal dichalcogenides (TMDs) have attracted widespread attention in the energy storage fields, especially its application in electrodes of LIBs. As a representative of TMDs, MoS 2 has shown fascinating and superior electrochemical performance due to its unique layered structure. [3,4] MoS 2 always exists in the following three phases: 2H, 1T, and 3R phase according to different coordinations of Mo and S atoms. [5][6][7][8][9] The 2H and 1T phase MoS 2 exhibit notable energy storage and conversion performance due to their characteristic structure and rich physical and chemical properties. 2H-MoS 2 is a semiconducting phase with trigonal prismatic structure. Its high theoretical capacity of 670 mAh g −1 renders it fit to be considered as a promising anode material for LIBs. [10,11] However, two severe issues of 2H-MoS 2 electrode still need to be taken into account: 1) the structure destruction induced by the large volume change during lithium-ions intercalating and deintercalating process; 2) the poor electronic conductivity, arising from a large bandgap of about 1.9 eV. [12,13] To overcome these shortcomings, a large amount of efforts was devoted to modify the electrochemical performance of 2H-MoS 2 . Two general ways are: 1) designing nanostructure materials, such as nanotubes, [14] nanosheets, [15] and nanospheres [16] ; 2) hybridizing 2H-MoS 2 with carbonaceous materials, such as graphene. [17,18] Compared with 2H phase MoS 2 , 1T phase MoS 2 presents a metallic transport behavior and its electric conductivity is approximately 5 orders of magnitudes higher than that in semiconducting 2H-MoS 2 . [19] This contributes to the transfer of electrons and ions in the electrode material. Furthermore, 1T-MoS 2 owns an expanded interlayer spacing of about 1 nm, which is nearly 1.5 times larger than that in 2H-MoS 2 (about 0.65 nm). [20,21] Such an expanded interlayer spacing makes lithium ions embedding and de-embedding much easier. However, the conventional methods to fabricate 1T-MoS 2 require an alkali metal intercalation or exfoliation process, which is unstable, dangerous, complicated, and time-consuming. [22] Preparing 1T phase MoS 2 possesses higher conductivity than the 2H phase, which is a key parameter of electrochemical performance for lithium ion batteries (LIBs). Herein, a 1T-MoS 2 /C hybrid is successfully synthesized through facile hydrothermal method with a proper glucose additive. The synthesized hybrid material is composed of smaller and fewer-layer 1T-MoS 2 nanosheets covered by thin carbon layers with an enlarged interlayer spacing of 0.94 nm. When it is used as an anode material for LIBs, the enlarged interlayer spacing facilitates rapid intercalating and deintercalating of lithium ions and accommodates volume change dur...

The synthetic process of the NiCoAl-LDH/V4C3Txcomposite and the assembled NiCoAl-LDH/V4C3Tx//AC hybrid supercapacitor device.