Sodium-ion hybrid capacitors (SICs) are emerging as promising devices that can balance energy and power output. However, the lack of a high-capacity cathode that can match the anode has limited its further application. In this work, we develop an efficient method to prepare spherical porous carbons (SPCs) with great specific surface area and narrow pore size distribution from coal-based humic acid via spray drying and a subsequent chemical activation process. Thanks to this unique porous structure, the SPC cathode has a superb capacity of 223 F g at 0.05 A g, as well as splendid rate performance and cycling stability. SICs constructed by an SPC cathode and hard carbon anode can exhibit a high energy density of 179.8 Wh kg at 155 W kg and achieved 89.4% capacity retention after 10 000 cycles at 0.5 A g. This outcome presents a viable approach to attaining high-capacity cathodes for constructing outstanding performance hybrid capacitors.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.langmuir.4c02138 | DOI Listing |
Dalton Trans
January 2025
Department of Chemistry and Centre for Energy Science, Indian Institute of Science Education and Research (IISER), Pune, Dr Homi Bhabha Road, Pune - 411008, India.
Organic-inorganic hybrid ferroelectric compounds of the halobismuthate family have emerged as a focal point of research owing to their reduced toxicity and distinctive optical characteristics. This study presents a novel ammonium hybrid perovskite, [BPMBDMA]·[Bi2Br9], which exhibits both ferro- and piezoelectric properties and crystallizes in the polar noncentrosymmetric 2 space group. The nonlinear optical (NLO) activity of [BPMBDMA]·[Bi2Br9] was corroborated through second harmonic generation measurements evidencing its noncentrosymmetric structure, which was further substantiated by piezoresponse force microscopy analyses.
View Article and Find Full Text PDFSmall
January 2025
Department of Material Science Engineering, Gachon University, Seongnamdaero 1342, Seongnam, 13120, Republic of Korea.
Herein, NaCl-templated mesoporous hard carbons (NMCs) have been designed and engineered with tunable surface properties as anode materials for potassium-ion batteries (KIBs) and hybrid capacitors (KICs). By utilizing "water-in-oil" emulsions, the size of NaCl templates is precisely modified, leading to smaller particles that enable the formation of primary carbon structures with reduced particle size and secondary structures with 3D interconnected mesoporosity. These features significantly enhance electrode density, reduce particle-to-particle resistance, and improve electrolyte wettability.
View Article and Find Full Text PDFMicromachines (Basel)
November 2024
Instituto Nacional de Astrofísica, Óptica y Electrónica-INAOE, Puebla 72840, Mexico.
This work presents the design, fabrication, and rigorous validation of a flexible, wireless, capacitive pressure sensor for the full-range continuous monitoring of ventricular pressure. The proposed system consists of an implantable set and an external readout device; both modules were designed to form an RCL resonant circuit for passive, wireless pressure sensing and signal retrieving. Using surface micromachining and flexible electronics techniques, a two-variable capacitor array and a dual-layer planar coil were integrated into a flexible ergonomic substrate, avoiding hybrid-like connections in the implantable set.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Physics, Dalian University of Technology, Dalian 116024, P. R. China.
Gradient porous carbon has become a potential electrode material for energy storage devices, including the aqueous zinc-ion hybrid capacitor (ZIHC). Compared with the sufficient studies on the fabrication of ZIHCs with high electrochemical performance, there is still lack of in-depth understanding of the underlying mechanisms of gradient porous structure for energy storage, especially the synergistic effect of ultramicropores (<1 nm) and micropores (1-2 nm). Here, we report a design principle for the gradient porous carbon structure used for ZIHC based on the data-mining machine learning (ML) method.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, USA.
Negative capacitance (NC) effects in ferroelectrics can potentially break fundamental limits of power dissipation known as "Boltzmann tyranny." However, the origin of transient NC of ferroelectrics, which is attributed to two different mechanisms involving free-energy landscape and nucleation, is under intense debate. Here, we report the coexistence of transient NC and an S-shaped anomaly during the switching of ferroelectric hexagonal ferrites capacitor in an RC circuit.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!