CuS Microspheres with Tunable Interlayer Space and Micropore as a High‐Rate and Long‐Life Anode for Sodium‐Ion Batteries

Abstract

Layered transition metal sulfides (LTMSs) have tremendous commercial potential in anode materials for sodium‐ion batteries (SIBs) in large‐scale energy storage application. However, it is a great challenge for most LTMS electrodes to have long cycling life and high‐rate capability due to their larger volume expansion and the formation of soluble polysulfide intermediates caused by the conversion reaction. Herein, layered CuS microspheres with tunable interlayer space and pore volumes are reported through a cost‐effective interaction method using a cationic surfactant of cetyltrimethyl ammonium bromide (CTAB). The CuS–CTAB microsphere as an anode for SIBs reveals a high reversible capacity of 684.6 mAh g−1 at 0.1 A g−1, and 312.5 mAh g−1 at 10 A g−1 after 1000 cycles with high capacity retention of 90.6%. The excellent electrochemical performance is attributed to the unique structure of this material, and a high pseudocapacitive contribution ensures its high‐rate performance. Moreover, in situ X‐ray diffraction is applied to investigate their sodium storage mechanism. It is found that the long chain CTAB in the CuS provides buffer space, traps polysulfides, and restrains the further growth of Cu particles during the conversion reaction process that ensure the long cycling stability and high reversibility of the electrode material.

One‐Pot Synthesis of CuCo2S4 Sub‐Microspheres for High‐Performance Lithium‐/Sodium‐Ion Batteries

“…As presented in Figure 7, the Nyquist plots of CuCo 2 S 4 sub-microsphere for LIBs ( Figure 7a) and SIBs (Figure 7b) both include a semicircle in the high frequency region and an inclined line in the middle-low frequency region, corresponding to the charge transfer resistance and lithium/sodium-ion diffusion process. [50][51] The enhancement of cycling performance and rate capability performance of CuCo 2 S 4 for LIBs/SIBs benefits from the bimetallic synergistic effect and the sub-micro structure compared with the previously report (Table S1). This may be related to the formation of metal copper and cobalt during the conversion reaction, which will increase the conductivity of electrode.…”

Synthesis of CuS@CoS2 Double‐Shelled Nanoboxes with Enhanced Sodium Storage Properties

“…Developing efficient anode materials is highly desirable to promote the practical implementation of SIBs . Owing to the high capacity and good electrochemical reversibility, various metal sulfides, such as CoS x , CuS x , SnS x , FeS x , have been reported for sodium storage . However, most of them suffer from poor conductivity and large volume change during electrochemical reactions, which cause limited rate and cycling performance.…”

Heterostructured TiO2 Spheres with Tunable Interiors and Shells toward Improved Packing Density and Pseudocapacitive Sodium Storage

“…[18][19][20] This effect is able to enhance both of the rate performance and capacity reversibility of advanced energy storage devices. [23][24][25][26][27] As far as we know, the relationship between pseudocapacitance and interior/shell adjustments of spherical materials has rarely been involved. [21,22] Very recently, several previous works present some effective approaches for promoting the pseudocapacitive Li + /Na + storage through structural design and optimization of electrode materials, such as oxygen vacancy creation of metal oxides, size-decreasing, and active facets exposing of nanosheets, interlayer spacing expansion of 2D materials.…”

“…After the first several cycles, the curves illustrate apparent high voltage plateaus and become well overlapped, suggesting much safer sodium storage by avoiding the dendritic growth, as well as favorable capacity reversibility. [24][25][26][27][28][29][35][36][37][38][39][40] The irreversible loss of capacity in these anodes can in some cases be offset by prelithiation/sodiation technologies. [41,42] Figure 3d demonstrates the cycling properties of the three as-prepared TiO 2 samples at low rate of 0.2 A g −1 .…”