Harnessing Plasma‐Assisted Doping Engineering to Stabilize Metallic Phase MoSe₂for Fast and Durable Sodium‐Ion Storage

Abstract

Metallic‐phase selenide molybdenum (1T‐MoSe2) has become a rising star for sodium storage in comparison with its semiconductor phase (2H‐MoSe2) owing to the intrinsic metallic electronic conductivity and unimpeded Na+ diffusion structure. However, the thermodynamically unstable nature of 1T phase renders it an unprecedented challenge to realize its phase control and stabilization. Herein, a plasma‐assisted P‐doping‐triggered phase‐transition engineering is proposed to synthesize stabilized P‐doped 1T phase MoSe2 nanoflower composites (P‐1T‐MoSe2 NFs). Mechanism analysis reveals significantly decreased phase‐transition energy barriers of the plasma‐induced Se‐vacancy‐rich MoSe2 from 2H to 1T owing to its low crystallinity and reduced structure stability. The vacancy‐rich structure promotes highly concentrated P doping, which manipulates the electronic structure of the MoSe2 and urges its phase transition, acquiring a high transition efficiency of 91% accompanied with ultrahigh phase stability. As a result, the P‐1T‐MoSe2 NFs deliver an exceptional high reversible capacity of 510.8 mAh g−1 at 50 mA g−1 with no capacity fading over 1000 cycles at 5000 mA g−1 for sodium storage. The underlying mechanism of this phase‐transition engineering verified by profound analysis provides informative guide for designing advanced materials for next‐generation energy‐storage systems.

Synergistic Engineering of Heterointerface and Architecture in New‐Type ZnS/Sn Heterostructures In Situ Encapsulated in Nitrogen‐Doped Carbon Toward High‐Efficient Lithium‐Ion Storage

“…[28] The b-values measured for ZnS/Sn@NPC electrode (Figure 3i) is located within the range between 0.738 and 0.849, manifesting it is a capacitive-controlled Li + storage mechanism. [29] The capacitive contribution ratios of the ZnS/Sn@NPC electrode (Figure 3j) are gradually increased to 74% (Figure S13a, Supporting Information) with the scan rates rising from 0.1 to 1 mV s −1 , which is much higher than that of ZnS@NC (59.5%) at 1 mV s −1 (Figure S14, d) Rate performances of ZnS/Sn@NPC, ZnS@NC, and SnS 2 electrodes at various current densities. e) Comparison of rate performance of the ZnS/Sn@NPC electrode with previously reported ZnS-based and other heterogeneous electrodes.…”

Aliovalent doping engineering enables multiple modulations of FeS2anodes to achieve fast and durable sodium storage

“…S6†). 33,34 This substitution will induce lattice defects and cause lattice distortion in the crystal materials to some extent, facilitating the fast intercalation/de-intercalation reaction of Na + . In addition, Raman spectra were collected to analyze the existence of a carbon layer in the P–FeS 2 @C composite, which was attributed to the low-intensity peak of the carbon materials in the XRD patterns compared to the high-intensity peaks of FeS 2 .…”

“…S9,† of particular note is that the S 2p peaks of P–FeS 2 @C also slightly shift to a lower binding energy relative to those of FeS 2 @C, which may be attributed to the introduction of P with lower electronegativity in FeS 2 . 33,41–43 The characteristic peaks at 284.6, 285.9 and 288.3 eV detected in the high-resolution C 1s spectrum (Fig. S10†) are associated with the CC, C–N, and C–O bonds, respectively.…”

“…Furthermore, the proportion of capacitive contribution was quantitatively inferred using the following equation: 33 i ( v ) = k 1 v + k 2 v 1/2 where k 1 v and k 2 v 1/2 are associated with the capacitive- and diffusion-controlled contribution, respectively. As portrayed in the shaded area of Fig.…”

Atomic Layer Engineering of TMDs by Modulation of Top Chalcogen Atoms: For Electrical Contact and Chemical Doping

“…17 However, it is difficult to uniformly apply these techniques on a large area. Novel approaches that involve reducing the contact resistance by the transition from a trigonal-prismatic 2H phase to an octahedral 1T phase through chemical doping, 18 the spatial arrangement and defect generation of chalcogen atoms such as S or Te in TMDs with laser-induced phase patterning, 19 and plasma irradiation 20 have also been reported. In addition, Liang et al recently reviewed various strategies for 2H to 1T phase transition process via defect engineering.…”