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09 May 2023, Volume 38 Issue 3
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Abstract
The solid-state “Mn0.75Ni0.25CO3/GNS asymmetric supercapacitor had a specific capacitance of 46-22 F g-1 at varied current densities (0.5-9.0 A g-1). The Mn0.75Ni0.25CO3/GNS asymmetric supercapacitor device as-fabricated demonstrated a power density of 499 W kg-1 at a high specific energy density of 25 Wh kg-1, and the solid-state ASC maintained 88% capacitance even after 7500 cycles, which is another benefit and suitable for commercial applications. Electrochemical impedance spectroscopy experiments were performed on all the materials produced in the half-cell, three-electrode, and two-electrode systems. The LMNCO-950 electrode represented the lowest Rs (2.18) and Rct (39.18) values, confirming the material is relatively stable and excellent. The Li+ diffusion co-efficient of LMNCO-950 (2.783 x10-15) is significantly higher than the LMNCO-800 (1.367 x10-15), LMNCO-900 (2.767 x10-15), and LMNCO-1000 (1.647 x10-15) samples. The obtained Rct values for H-CMO at the third and 500th cycles are 285 and 396, 267 and 355 for P-CMO, and 186 and 262 for GW-P-CMO. The GW-P-CMO electrode outperformed the other two in terms of capacity retention and had a lower Rct. The best Li-ion diffusion coefficient, lowest Rs and Rct values, and very stable material interfaces even after extended cycling without disintegration are all indicators of this. The porous, smaller particle size, and high active surface area natured Mn based nano structures, which support the greater electrode/electrolyte interface and, consequently, good electrochemical performance, are responsible for the lowered Rct values. Another option is the quicker transfer of charged particles between the electrode and electrolyte. These material properties improve electrochemical performances by resulting in high specific capacitance and superior capacity retention properties. Cyclic stability is crucial for energy storage applications and is required for renewable energy storage systems and hybrid electric vehicles.”
Keyword
Sub-Microsphers, Positive, Electrodes, Solid State, Asymmetric Supercapacitors, Low-Cost Metal Oxide.
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