From crystalline to amorphous: heterostructure design of MoO₂/MoS₂in situ supported by nitrogen-doped carbon with robust sodium storage at −40 °C

Abstract

The restricted interfacial kinetics, increased charge-transfer resistance, and low diffusion coefficient account for the unsatisfied electrochemical performances of sodium-ion batteries at low temperatures. The commonly used anode materials are crystalline,...

Dual modification of Ti3C2Tx MXene hybridization and cut-off voltage adjustment for MoS2 to achieve stable sodium storage performance

“…S7, ESI †). 37 In contrast, the specific capacity of DCV-0.05 V (from 304.1 to 93.2 mA h g À1 ) and DCV-0.1 V (from 157.6 to 65.4 mA h g À1 ) at 1.0 A g À1 deteriorates with the increase of cycling number. The comparison of electrochemical performance of MOS 2 /Ti 3 C 2 T x within 0.2-3.0 V with other related studies focused on the optimization of voltage window for layered electrode materials is listed in Table S1 (ESI †), where the MoS 2 /Ti 3 C 2 T x reported in this work manifests comparable sodium storage performance.…”

“…31 Meanwhile, the gradually increased peak intensity of Na x MoS 2 reveals the favourable intercalation of Na + into the MoS 2 /Ti 3 C 2 T x with the increase of discharge cut-off voltage. 37 Note that both the MoS 2 and Ti 3 C 2 T x are typical layered structures with large lattice spacing, which may facilitate the transportation of Na + . 18,19 As shown, the ex situ XRD results clearly confirm that the deep conversion reaction of the MoS 2 /Ti 3 C 2 T x electrode can be effectively restricted through increasing the discharge cut-off voltage.…”

MoS2@C with S vacancies vertically anchored on V2C-MXene for efficient lithium and sodium storage

“…3g and h), which should be attributed to the fact that the strong interaction between V 2 C-MXene and MoS 2 @C induced electron transfers and resulted in the lower Mo oxidation states, higher V oxidation states and more S vacancies in f-V 2 C–MoS 2 @C, consistent with the Raman and EPR results. 18,35,63…”

“…61,66,67 The b value could be determined by the slope of the log(i)-log(v) plot using eqn (6), and b = 0.5 and b = 0.1 implied that the diffusion-controlled process and surfacecontrolled pseudo-capacitive behaviors dominated the charge storage process, respectively. [63][64][65]68 The smaller movement in the position of the redox peaks with increasing scan rates (Fig. 5a-c) and the much higher b values (Fig.…”

“…3g and h), which should be attributed to the fact that the strong interaction between V 2 C-MXene and MoS 2 @C induced electron transfers and resulted in the lower Mo oxidation states, higher V oxidation states and more S vacancies in f-V 2 C-MoS 2 @C, consistent with the Raman and EPR results. 18,35,63 TGA measurements were performed to estimate the content of V 2 C-MXene, C and MoS 2 in the as-prepared materials, and the results are shown in Fig. 3i.…”