No abstract

No abstract

Self-supported carbon electrodes have been intensively explored in the fields of materials chemistry, energy storage, and conversion due to the unique features of carbon materials. Herein, we report a facile strategy to construct a freestanding carbon membrane (CM) electrode consisting of a microfiltration CM and two-dimensional (2D) ultrathin Co 3 O 4 nanosheets (NSs), which is successfully applied as an efficient and binder-free carbon electrode in the electrochemical applications of enzyme-free glucose detection and supercapacitors. Owing to the inherent structural merits, including the three-dimensional (3D) interconnected porous network in the membrane, structural integrity, high conductivity, and the well-dispersed and in situ growth of 2D Co 3 O 4 NSs, the obtained Co 3 O 4 NSs/CM demonstrated superior electrochemical performances and excellent long-term operation stability. Our present work paves the path to fabricate low-cost and efficient carbon electrodes with a rational structure design for multifunctional materials.

Lithium−sulfur (Li−S) batteries, despite their superior gravimetric energy density, are inferior to lithium-ion (Li-ion) batteries in terms of volumetric energy density because of the intrinsic low density of sulfur and the lightweight carbon host. Here, a new strategy is proposed to improve the volumetric capacity of sulfur cathode with selenium-doped sulfurized poly(acrylonitrile) (SPAN) as the electrode material. The introduction of Se not only accelerates the redox kinetics of sulfur conversion but also leads to dramatically enhanced active materials content and higher tap density of the electrode material. Consequently, the Se 0.4 SPAN composite delivers an impressive volumetric capacity of 1185 mAh cm −3 at 0.1 C, a high rate capability of 850 mAh cm −3 at 4 C, and excellent long-term stability over 500 cycles at 1 C. Self-discharge behavior and the shuttle effect are completely avoided due to the absence of soluble intermediates. Moreover, a remarkable volumetric energy density of 1537 Wh L cathode −1 is achieved based on the densification effect with a high cathode density (1.51 g cm −3 ), which is comparable to the metal oxide cathode of Li-ion batteries. This study demonstrates a promising way to overcome the bottlenecks of current Li−S technologies for high volumetric-energy-density rechargeable batteries.

No abstract