ABSTRACT
Searching for high-performance Ni-based cathodes plays an important role in developing better aqueous nickel-zinc (Ni-Zn) batteries. For this purpose, herein, we demonstrate the design and synthesis of ultrathin α-Ni(OH)2 nanosheets branched onto metal-organic frameworks (MOFs)-derived 3D cross-linked N-doped carbon nanotubes encapsulated with tiny Co nanoparticles (denoted as Co@NCNTs/α-Ni(OH)2), which are directly supported on a flexible carbon cloth (CC). An aqueous Ni-Zn battery employing the hierarchical CC/Co@NCNTs/α-Ni(OH)2 as the binder-free cathode and a commercial Zn plate as the anode is fabricated, which displays an ultrahigh capacity (316 mAh g-1) and energy density (540.4 Wh kg-1) at 1 A g-1 as well as excellent rate capability (238 mAh g-1 at 10 A g-1) and superior cycling performance (about 84% capacity retention after 2000 cycles at 10 A g-1). The impressive electrochemical performance might benefit from the rich active sites, rapid electron transfer, cushy electrolyte access, rapid ion transport, and robust structural stability. In addition, the quasi-solid-state CC/Co@NCNTs/α-Ni(OH)2//Zn batteries are also successfully assembled with polymer electrolyte, indicating the great potential for portable and wearable electronics. This work might provide important guidance for constructing carbon-based hybrid materials directly supported on conductive substrates as high-performance electrodes for energy-related devices.
ABSTRACT
Developing high-performance cathode host materials is fundamental to solve the low utilization of sulfur, the sluggish redox kinetics, and the lithium polysulfide (LiPS) shuttle effect in lithium-sulfur batteries (LSBs). Here, a multifunctional Ag/VN@Co/NCNT nanocomposite with multiple adsorption and catalytic sites within hierarchical nanoreactors is reported as a robust sulfur host for LSB cathodes. In this hierarchical nanoreactor, heterostructured Ag/VN nanorods serve as a highly conductive backbone structure and provide internal catalytic and adsorption sites for LiPS conversion. Interconnected nitrogen-doped carbon nanotubes (NCNTs), in situ grown from the Ag/VN surface, greatly improve the overall specific surface area for sulfur dispersion and accommodate volume changes in the reaction process. Owing to their high LiPS adsorption ability, outer Co nanoparticles at the top of the NCNTs catch escaped LiPS, thus effectively suppressing the shuttle effect and enhancing kinetics. Benefiting from the multiple adsorption and catalytic sites of the developed hierarchical nanoreactors, Ag/VN@Co/NCNTs@S cathodes display outstanding electrochemical performances, including a superior rate performance of 609.7 mAh g-1 at 4 C and a good stability with a capacity decay of 0.018% per cycle after 2000 cycles at 2 C. These properties demonstrate the exceptional potential of Ag/VN@Co/NCNTs@S nanocomposites and approach LSBs closer to their real-world application.
ABSTRACT
@#AIM: To analyze the influence of trifocal lens(AT LISA tri 839MP), Lenstec SBL-3 intraocular lens(IOL)and T SPHERIS 209M monofocal IOL implantation on vision and visual quality of patients with age-related cataract(ARC). <p>METHODS: Totally 114 patients(114 eyes)with ARC undergoing elective surgical treatment in the hospital between October 2018 and April 2019 were enrolled in the prospective clinical study. They were divided into LISA tri group, SBL group and monofocal group with 38 cases(38 eyes)in each group. They were treated with trifocal IOL(AT LISA tri 839MP), Lenstec SBL-3 IOL and CT SPHERIS 209M monofocal IOL, respectively. The corneal endothelium, vision and visual quality before operation and 3mo after operation were compared. <p>RESULTS:Three months after operation, no significant changes in corneal endothelial cell density(ECD), central corneal thickness(CCT)and the proportion of hexagonal cells in the three groups compared with preoperation(<i>P</i>>0.05), while the uncorrected distance visual acuity(UCDVA), uncorrected intermediate visual acuity(UCIVA)and uncorrected near visual acuity(UCNVA)were significantly improved(<i>P</i><0.001). UCDVA, UCIVA and UCNVA of LISA tri group were(0.11±0.03)LogMAR,(0.17±0.05)and(0.09±0.02), which of SBL group were(0.12±0.02, 0.19±0.05, 0.08±0.02), all significantly better than(0.21±0.04, 0.24±0.07, 0.15±0.03)in monofocal group(<i>P</i><0.05). 3mo after operation, the near off-glasses rate and visual satisfaction in LISA tri group were 92% and 97%, which in SBL group were 95% and 92%, all significantly higher than 66% and 68% in monofocal group(<i>P</i><0.017). Compared with preoperation, the visual function and quality of life(VF-QOL)scores of the three groups significantly increased(<i>P</i><0.001), which were significantly higher in LISA tri group and SBL group than in monofocal group(<i>P</i><0.05). <p>CONCLUSION: Trifocal IOL(AT LISA tri-839MP)and Lenstec SBL-3 multifocal IOL implantation is superior to monofocal IOL in the treatment of patients with ARC, which can effectively improve vision and visual quality.
ABSTRACT
@#AIM: To compare the therapeutic effects of phacoemulsification respectively combined with diffractive multifocal intraocular lens(IOL)and monofocal IOL implantation in the treatment of cataract. <p>METHODS: A total of 99 cataract patients(145 eyes)who underwent phacoemulsification combined with IOL implantation in the hospital from January 2015 to February 2019 were divided into observation group(<i>n</i>=51, 75 eyes)and control group(<i>n</i>=48, 70 eyes)according to the non-randomized clinical trial and patient voluntary principles. The observation group was treated with diffractive multifocal IOL implantation, while the control group was treated with monofocal IOL implantation. The visual acuity, corneal endothelial cell count, loss rate of corneal endothelial cells, results of corneal topography, and contrast sensitivity(CS)in daytime, day glare time, nighttime and night glare time were compared between two groups. The complications and spectacles-independent rate were counted. <p>RESULTS: At 1wk, 1mo and 3mo, there were no significant differences in the best corrected distance visual acuity(BCDVA)and best corrected near visual acuity(BCNVA)between two groups(<i>P</i>>0.05). However, the uncorrected distance visual acuity(UCDVA)at 1wk and 1mo, the uncorrected near visual acuity(UCNVA)and the distance corrected near visual acuity(DCNVA)at 1wk, 1mo and 3mo of the observation group were significantly lower than those of the control group(<i>P</i><0.05). After surgery, corneal endothelial cell counts and astigmatism of two groups decreased significantly. No significant differences were found in corneal endothelial cell count, loss rate of corneal cells and astigmatism between two groups(<i>P</i>>0.05). CS in daytime of 1.5c/d frequency band, in day glare time of 1.5c/d, 3c/d and 6c/d frequency bands, in nighttime of 3c/d and 18c/d frequency bands, in night glare time of 3c/d, 6c/d and 18 c/d frequency bands were significantly lower, while CS in daytime of 12c/d frequency band was significantly higher in the observation group than in the control group. There was no significant difference in the incidence of complications between two groups(<i>P<</i>0.05), but the spectacles-independent rate was significantly higher in the observation group than in the control group(<i>P</i><0.05). <p>CONCLUSION: Phacoemulsification combined with diffractive multifocal IOL implantation can obtain good total range visual acuity, with a higher spectacles-independent rate and relatively low CS after surgery.
