Extrinsic pseudocapacitive ultrathin 2D MoS2 nanoflakes clamped on 1D Sb2S3 nanorods: an advanced heterostructured anode for high-energy ammonium ion hybrid capacitors

Abstract

Ammonium-ion (NH4+) charge carriers have recently been considered promising for electrochemical energy storage (EES) systems because of their high safety, low molar mass, and small hydrated radius (3.31 & Aring;). However, finding a kinetically balanced anode and cathode combination for high NH4+-ion storage is challenging. Herein, a new approach for developing a heterostructured electrode was developed by constructing extrinsic pseudocapacitive 2D ultrathin MoS2 nanoflakes clamped on 1D Sb2S3 nanorods (MoS2/Sb2S3) as an anode for high-performance ammonium-ion hybrid capacitors (AIHCs) against the intrinsic pseudocapacitive MnO2 cathode. The engineered MoS2/Sb2S3 heterostructured anode facilitated large interlayer galleries owing to the presence of 2D MoS2 for facial NH4+-ion diffusion and provided a rapid electron pathway through 1D Sb2S3, which promoted a high capacitance of 360 F g(-1), low resistance, and stable cycling performance. More importantly, the constructed AIHC delivered a superior energy density of 43.75 W h kg(-1) at a power density of 600 W kg(-1) and excellent cycling durability over 5000 cycles. These results show that a heterostructured extrinsic pseudocapacitive anode can improve the electrochemical parameters of NH4+ EES systems and replace traditional carbon-based anode materials.