Δ-type manganese oxides with preintercalated sodium ions as atomic pillars for high-performance supercapacitors. (20th October 2022)

• Record Type: Journal Article
• Authors: Tsai, Chun-Yi; Su, Tzu-Sen; Wei, Tzu-Chien; Wu, Mao-Sung
• Is Part Of: Electrochimica acta. Volume 430(2022)
• Publication Date: 2022-10-20
• Subjects: Birnessite -- Layered manganese oxide -- Na+-intercalated compounds -- Supercapacitors; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2022.141107
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Layered δ-MnO2 (Birnessite) with interlayered H2 O molecules has been considered as a promising candidate for supercapacitor application. However, severe drawbacks of δ-MnO2 owing to its structural deformation by Mn 2+ dissolution and Jahn-Teller distortion cause poor durability and low capacity for energy storage. Herein, we report a δ-type Na0.16 MnO2 electrode with enhanced capacitance and cycling performance synthesized by preintercalation of Na + ions. The Na0.16 MnO2 has a large amount of interlayered H2 O molecules and stabilized Mn-O-Na bonds between MnO6 layers for facilitating ionic diffusion. In addition, the Na0.16 MnO2 shows the homogeneously interconnected ultrathin nanosheet network for fast charge-storage kinetics, large storage capacity, and superior cycling stability. The specific capacitance of Na0.16 MnO2 reaches 560 F g −1 at a current density of 1 A g −1, while maintaining constant capacity up to 10, 000 cycles. The enhanced performance of Na0.16 MnO2 is mainly attributed to the atomic pillars of preintercalated Na + ions in δ-MnO2 which effectively suppress the deformation of interlayer spacing during charge/discharge processes and thus benefit the long-term stability.