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1.
J Colloid Interface Sci ; 645: 33-44, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37146377

ABSTRACT

HYPOTHESIS: The introduction of functional interlayers for efficient anchoring of lithium polysulfides has received significant attention worldwide. EXPERIMENTS: A facile wet-chemical method was adopted to obtain hollow porous carbon nanospheres (HPCNSs) impregnated with metallic and polar cobalt sulfide (Co9S8) nanocrystals (abbreviated as "Co9S8@HPCNS"). The prepared nanocrystals were employed as electrocatalytic interlayers via separator coating for the efficient capture and reutilization of polysulfide species in Li-S batteries. The HPCNSs were synthesized via the polymerization method followed by carbonization and template removal. The Co9S8 nanocrystals were impregnated inside the HPCNSs, followed by heat treatment in a reducing atmosphere. FINDINGS: The porous structure of the CNS enables the efficient percolation of the electrolyte, in addition to accommodating unwanted volume fluctuations during redox processes. Furthermore, the metallic Co9S8 nanocrystals improve the electronic conductivity and enhance the polarity of the CNS towards the polysulfide. Correspondingly, the Li-S cells featuring Co9S8@HPCNS as electrocatalytic interlayers and regular sulfur (S) electrodes display improved electrochemical performance such as reasonable rate performance and prolonged cycling stability at different current rates (0.1, 0.5, and 1.0 C). Therefore, we anticipate that the rational design strategy proposed herein will provide significant insights into the synthesis of advanced materials for various energy storage applications.

2.
Medicine (Baltimore) ; 101(45): e31431, 2022 Nov 11.
Article in English | MEDLINE | ID: mdl-36397407

ABSTRACT

This study aimed to investigate the long-term clinical efficacy of and satisfaction with integrative Korean medicine (KM) treatment in patients with shoulder osteoarthritis (SOA). We conducted a prospective observational study of patients with SOA. Patients aged 19 years and older who underwent inpatient treatment for more than 1 week were eligible for enrollment in the study. The primary evaluation index was the numeric rating scale for shoulder pain. Sub-evaluation indices included the Shoulder Pain and Disability Index for shoulder function, EuroQol-5-dimension score for overall quality of life, and Patient Global Impression of Change. Outcome measures were assessed at admission, discharge, and follow-up. For the follow-up questionnaire survey, the following information was collected: current status, surgery after discharge, reasons for finding integrative KM treatment satisfactory/unsatisfactory, and quality of life after discharge. In total, 186 patients were enrolled in the primary analysis, and 103 patients completed the follow-up survey. The mean number of days of follow-up was 1019 ±â€…439. Compared with the baseline, the mean differences in the numeric rating scale and Shoulder Pain and Disability Index were 3.05 ±â€…0.34 and 36.06 ±â€…5.53, respectively. Regarding the Patient Global Impression of Change, 89 out of 103 (86.4%) patients chose "minimally improved" or better. Furthermore, the EuroQol-5-dimension score also increased, showing an improvement of health-related quality of life after treatment. Integrative KM treatment is a potential option for reducing pain severity and improving function and health-related quality of life in patients with SOA. Prospective randomized studies would support this finding for the next step.


Subject(s)
Inpatients , Osteoarthritis , Humans , Follow-Up Studies , Quality of Life , Prospective Studies , Shoulder Pain/therapy , Shoulder , Osteoarthritis/therapy , Republic of Korea
3.
Nanomicro Lett ; 14(1): 17, 2021 Dec 06.
Article in English | MEDLINE | ID: mdl-34870769

ABSTRACT

Two-dimensional (2D) MXenes are promising as electrode materials for energy storage, owing to their high electronic conductivity and low diffusion barrier. Unfortunately, similar to most 2D materials, MXene nanosheets easily restack during the electrode preparation, which degrades the electrochemical performance of MXene-based materials. A novel synthetic strategy is proposed for converting MXene into restacking-inhibited three-dimensional (3D) balls coated with iron selenides and carbon. This strategy involves the preparation of Fe2O3@carbon/MXene microspheres via a facile ultrasonic spray pyrolysis and subsequent selenization process. Such 3D structuring effectively prevents interlayer restacking, increases the surface area, and accelerates ion transport, while maintaining the attractive properties of MXene. Furthermore, combining iron selenides and carbon with 3D MXene balls offers many more sites for ion storage and enhances the structural robustness of the composite balls. The resultant 3D structured microspheres exhibit a high reversible capacity of 410 mAh g-1 after 200 cycles at 0.1 A g-1 in potassium-ion batteries, corresponding to the capacity retention of 97% as calculated based on 100 cycles. Even at a high current density of 5.0 A g-1, the composite exhibits a discharge capacity of 169 mAh g-1.

4.
Small ; 16(33): e2002345, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32686320

ABSTRACT

Potassium-ion batteries (KIBs) are considered as promising alternatives to lithium-ion batteries owing to the abundance and affordability of potassium. However, the development of suitable electrode materials that can stably store large-sized K ions remains a challenge. This study proposes a facile impregnation method for synthesizing ultrafine cobalt-iron bimetallic selenides embedded in hollow mesoporous carbon nanospheres (HMCSs) as superior anodes for KIBs. This involves loading metal precursors into HMCS templates using a repeated "drop and drying" process followed by selenization at various temperatures, facilitating not only the preparation of bimetallic selenide/carbon composites but also controlling their structures. HMCSs serve as structural skeletons, conductive templates, and vehicles to restrain the overgrowth of bimetallic selenide particles during thermal treatment. Various analysis strategies are employed to investigate the charge-discharge mechanism of the new bimetallic selenide anodes. This unique-structured composite exhibits a high discharge capacity (485 mA h g-1 at 0.1 A g-1 after 200 cycles) and enhanced rate capability (272 mA h g-1 at 2.0 A g-1 ) as a promising anode material for KIBs. Furthermore, the electrochemical properties of various nanostructures, from hollow to frog egg-like structures, obtained by adjusting the selenization temperature, are compared.

5.
Nanomicro Lett ; 13(1): 9, 2020 Oct 27.
Article in English | MEDLINE | ID: mdl-34138196

ABSTRACT

In this work, a novel vacuum-assisted strategy is proposed to homogenously form Metal-organic frameworks within hollow mesoporous carbon nanospheres (HMCSs) via a solid-state reaction. The method is applied to synthesize an ultrafine CoSe2 nanocrystal@N-doped carbon matrix confined within HMCSs (denoted as CoSe2@NC/HMCS) for use as advanced anodes in high-performance potassium-ion batteries (KIBs). The approach involves a solvent-free thermal treatment to form a Co-based zeolitic imidazolate framework (ZIF-67) within the HMCS templates under vacuum conditions and the subsequent selenization. Thermal treatment under vacuum facilitates the infiltration of the cobalt precursor and organic linker into the HMCS and simultaneously transforms them into stable ZIF-67 particles without any solvents. During the subsequent selenization process, the "dual confinement system", composed of both the N-doped carbon matrix derived from the organic linker and the small-sized pores of HMCS, can effectively suppress the overgrowth of CoSe2 nanocrystals. Thus, the resulting uniquely structured composite exhibits a stable cycling performance (442 mAh g-1 at 0.1 A g-1 after 120 cycles) and excellent rate capability (263 mAh g-1 at 2.0 A g-1) as the anode material for KIBs.

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