Single crystals of a bismuth-based coordination polymer (CP) with carboxyl-thiol ligands, [Bi(C₈H₂O₄S₂)(C₂H₈N)]_n (Bi-DSBDC-DMA, DMBDC = 2,5-disulfur-1,4-dicarboxylate, DMA = dimethylamine), have been successfully synthesized. X-ray diffraction analysis reveals that Bi-DSBDC-DMA possesses a layered structure, with two-dimensional (2D) Bi-DSBDC networks alternating with layers composed of dimethylamine ions. This material demonstrates semiconducting properties, featuring an optical bandgap of 2.2 eV and an electrical conductivity of 2 × 10⁻⁸ S/cm. Furthermore, electrodes based on this material exhibit a capacity of 250 mAh/g after 200 cycles for lithium-ion storage.

Nickel-rich layered oxides are attractive cathode for lithium-ion batteries (LIBs) because of the high energy density and low cost. The critical problem is capacity fading caused by the highly reactive metastable phases under voltages of higher than 4.15 V. Herein, we find that facile Ar/H₂ plasma treating could produce oxygen vacancies that will readily transform into homogeneous spinel layer (~ 6 nm) on the LiNi_0.8Co_0.1Mn_0.1O₂ (NCM₈₁₁) surface after a few cycles of lithiation/delithiation procedure. Owing to the structural matching between spinel and layered structure, the diffusion of Li ions could remain fast upon cycling. Besides, the spinel layer is electrochemically inert, which guarantees surface stabilization and inhibits the detrimental phase transition from H2 to H3 at high voltages. Under the protection of the homogeneous spinel layer, the NCM₈₁₁ electrode shows superior capacity retention of 91.2% after 200 cycles at the current density of 100 mA·g⁻¹. This work proposes a novel strategy of surface reconstruction to stabilize nickel-rich layered oxide materials for LIBs.

It is a big challenge to well control the porous structure of carbon materials for supercapacitor application. Herein, a simple in-situ self-templating strategy is developed to prepare three-dimensional (3D) hierarchical porous carbons with good combination of micro and meso-porous architecture derived from a new oxygen-bridged porous organic polymer (OPOP). The OPOP is produced by the condensation polymerization of cyanuric chloride and hydroquinone in NaOH ethanol solution and NaCl is in-situ formed as by-product that will serve as template to construct an interconnected 3D hierarchical porous architecture upon carbonization. The large interface pore architecture, and rich doping of N and O heteroatoms effectively promote the electrolyte accessibility and electronic conductivity, and provide abundant active sites for energy storage. Consequently, the supercapacitors based on the optimized OPOP-800 sample display an energy density of 8.44 and 27.28 Wh·kg⁻¹ in 6.0 M KOH and 1.0 M Na₂SO₄ electrolytes, respectively. The capacitance retention is more than 94% after 10,000 cycles. Furthermore, density functional theory (DFT) calculations have been employed to unveil the charge storage mechanism in the OPOP-800. The results presented in this job are inspiring in finely tuning the porous structure to optimize the supercapacitive performance of carbon materials.

Herein, we prepared a bimetallic layered double hydroxide (FeCo LDH) featuring a dandelion-like structure. Anchoring of CeO₂ onto FeCo LDH produced interfaces between the functionalizing CeO₂ and the parent LDH. Comparative electrochemical studies were carried out. Onset potential, overpotential, and Tafel slope point to the superior oxygen-evolving performance of CeO₂-FeCo LDH with respect to FeCo LDH, therefore, demonstrating the merits of CeO₂ functionalization. The electronic structures of Fe, Co, and Ce were analyzed by X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS) from which the increase of Co³⁺ and the concurrent lowering of Ce⁴⁺ were established. With the use of CeO₂-FeCo LDH, accelerated formation at a sizably reduced potential of Co-OOH, one of the key intermediates preceding the release of O₂was observed by in situ Raman spectroscopy. We now have the atomic-level and location-specific evidence, the increase of the active Co³⁺ across the interface to correlate the enhanced catalytic performance with CeO₂ functionalization.

Potassium-ion batteries (PIBs) are promising next-generation energy storage candidates due to abundant resources and low cost. Sb-based materials with high theoretical capacity (660 mAh·g^–1) and low working potential are considered as promising anode for PIBs. The remaining challenge is poor stability and slow kinetics. In this work, FeSb@N-doped carbon quantum dots anchored in three-dimensional (3D) porous N-doped carbon (FeSb@C/N⊂3DC/N), a Sb-based material with a particular structure, is designed and constructed by a green salt-template method. As an anode for PIBs, it exhibits extraordinarily high-rate and long-cycle stability (a capacity of 245 mAh·g^–1 at 3, 080 mA·g^–1 after 1, 000 cycles). The pseudocapacitance contribution (83%) is demonstrated as the origin of high-rate performance of the FeSb@C/N⊂3DC/N electrode. Furthermore, the potassium storage mechanism in the electrode is systematically investigated through ex-situ characterization techniques including ex-situ transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Overall, this study could provide a useful guidance for future design of high-performance electrode materials for PIBs.