Yunling Jiang

TL;DR: In this paper , a review of the recent research progress in correlated single-atom catalysts (C-SACs) is presented, which shows that the control of metal-metal interactions enables regulation of atomic structure, local coordination, and electronic properties of metal single atoms.

TL;DR: The failure mechanism of Bi nanorods and the protective effect of the carbon shell are revealed by ex situ TEM, which illuminates the decreasing tendency in the initial 10-20 cycles and the subsequent stable trend of cyclic performance.

Abstract: The sodium storage performance of NiS2 suffer from low initial coulombic efficiency and poor cycling stability which are ascribed to the volume expansion and collapse of the structure during the charge/discharge transformation process. Compared with composites, encapsulating NiS2 in carbon framework is more effective in buffering for the volume expansion and enhancing the electronic conductivity of sodium‐ion batteries. In this work, NiS2 decorated with bifunctional carbon (NiS2@C@C), where nickel dimethylglyoxime and polyaniline are employed as the precursor and carbon source, respectively, are obtained. Since the introduced carbon layer suppresses the volume expansion and enhances both the electronic conductivity and charge transfer of Na+, the attained NiS2@C@C displays outstanding sodium storage performance. At a current density of 0.1 A g−1, a high reversible specific capacity of 580.8 mAh g−1 remains even after 100 cycles. The first coulombic efficiency (79.65%) and rate performance (448 mAh g−1 at 1.6 A g−1) of NiS2@C@C are also remarkable. Extraordinarily, the excogitation of NiS2 decorated with bifunctional carbon is also significant for the preparation of similar materials.