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991.
Qilan Chen;Junhao Li;Jiajie Pan;Tong Li;Kaixin Wang;Xu Li;Kaixiang Shi;Yonggang Min;Quanbing Liu; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(32):2401153
Lithium–sulfur batteries are recognized as the next generation of high-specific energy secondary batteries owing to their satisfactory theoretical specific capacity and energy density. However, their commercial application is greatly limited by a series of problems, including disordered migration behavior, sluggish redox kinetics, and the serious shuttle effect of lithium polysulfides. One of the most efficient approaches to physically limit the shuttle effect is the rational design of a hollow framework as sulfur host. However, the influence of the hollow structure on the interlayers has not been clearly reported. In this study, the Mo2C/C catalysts with hollow(H-Mo2C/C) and solid(S-Mo2C/C) frameworks are rationally designed to explore the dependence of the hollow structure on the interlayer or sulfur host. In contrast to the physical limitations of the hollow framework as host, the hollow structure of the interlayer inhibited lithium-ion diffusion, resulting in poor electrochemical properties at high current densities. Based on the superiority of the various frameworks, the H-Mo2C/C@S | S-Mo2C/C@PP | Li cells are assembled and displayed excellent electrochemical performance. This work re-examines the design requirements and principles of catalyst frameworks in different battery units. 相似文献
992.
《International Journal of Hydrogen Energy》2022,47(48):20894-20904
Developing non-noble metal oxygen reduction reaction (ORR) electrocatalysts with high performance, excellent stability, and low-cost is crucial for the industrialization of fuel cells. Herein, trace level Co modified 3D hybrid titanium carbonitride MXene and boron-carbon-nitrogen nanotubes catalyst (TiCN–BCN–Co) is fabricated by spray-lyophilization and high-temperature pyrolysis. This strategy not only avoids the oxidation of Ti3C2Tx MXene, but also introduces nitrogen atoms into the titanium carbide lattice to form a more electrocatalytically active TiCN crystal phase. The obtained TiCN–BCN–Co exhibits superior ORR catalytic activity with a positive half-wave potential of 0.83 V vs. RHE and outperforms commercial Pt/C in terms of stability and methanol tolerance. Impressively, the Zn-air battery with TiCN–BCN–Co cathode achieves a superior specific capacity of 791 mAh g?1 and long-term stability of 200 h. 相似文献
993.
994.
Jiajia Song;Lingjiang Kou;Yong Wang;Taotao Ai;Wenhu Li;Koji Kajiyoshi;Panya Wattanapaphawong;Yi Li; 《International Journal of Applied Ceramic Technology》2024,21(1):319-326
Energy density, power density, as well as the cost of aqueous zinc-ion batteries (AZIBs), are largely determined by the cathode material. Among the various cathodic candidates, vanadium-based materials with various oxidation states of vanadium cations and open frameworks have emerged as highly promising options. In this work, a heterogeneous with hydrangea-like (NH4)2V4O9/V5O12·6H2O as cathode materials for AZIBs. The hydrogen bonds formed by NH4+ of (NH4)2V4O9, in conjunction with the lattice water in V5O12·6H2O, sufficiently strengthen the cohesion of the layered structure and expand the interlayer space. As a result, accelerating the diffusion of Zn2+ ultimately leads to an enhanced overall discharge capacity. Remarkably, the hydrangea-like (NH4)2V4O9/V5O12·6H2O electrode at a current density of 100 mA g−1 shows a high reversible capacity of 209 mAh g−1 after 150 cycles and higher rate capability (172 mAh g−1 at 500 mA g−1). The outstanding electrochemical performance can be attributed to the unique structure of the cathode material and accelerated diffusion coefficient of Zn2+. 相似文献
995.
996.
《International Journal of Hydrogen Energy》2019,44(2):1078-1087
Carbon particles modified macroporous Si/Ni composite (MP-Si/Ni/C) is easily obtained via a facile fabrication of porous Si/Ni precursor by dealloying SiNiAl alloy followed by a surface growth of carbon nanoparticles. MP-Si/Ni/C composite possesses the multiply conductivity modification that are built through mixing Ni dispersoid and growing one layer of carbon particles. Coupled with the structural advantages of interconnected network backbone, rich voids, and the coated carbon particles, MP-Si/Ni/C exhibits dramatically enhanced lithium storage performances with excellent reversible capacity, enhanced rate performance, as well as outstanding cycling stability compared with pure MP-Si and MP-Si/Ni. Especially, the reversible capacity remains up to 1113.1 and 708.8 mA h g−1 at the current densities of 200 and 1000 mA g−1 after 120 cycles, respectively. Besides, it shows excellent rate capability even when continuously cycled at high current density of 3000 mA g−1. With the advantages of unique structure, excellent performances, and facile preparation, the as-made MP-Si/Ni/C composite shows promising application potential as an alternative anode for lithium ion batteries. 相似文献
997.
《International Journal of Hydrogen Energy》2019,44(14):7438-7447
Porous carbon derived from rice husk has been prepared and subsequently be used as carbon support to in situ fabricate hierarchical MoS2 microspheres. The X-ray powder diffraction characterization indicates that the graphite structure exists in the obtained rice husk carbon which is beneficial for the enhancement of the charge transfer speed. MoS2 microspheres on the surface of rice husk carbon present hierarchical structure with nanosheet subunit, and exhibits looser morphology than the individual MoS2 due to the lattice shrinkage. Based on the synergistic effect of MoS2 and the rice husk carbon, MoS2@RHC composite displays excellent lithium storage performance. The charge-transfer resistance of the MoS2@RHC composite is great lower than that of the individual materials. This result leads to the superior cycling stability and rate capability based on the favorable interface kinetics with faster lithium ion diffusion. The lithium charge-discharge mechanism of the composite is also further investigated. The log (peak current) versus log (scan rate) plot reveals that the current is predominantly controlled by the diffusion kinetics during the lithiation and delithiation process. 相似文献
998.
《International Journal of Hydrogen Energy》2019,44(45):24369-24376
Nitrogen self-doped graphene (N/G) nanosheets were prepared through magnesiothermic reduction of melamine. The obtained N/G features porous structure consisting of multi-layer nanosheets. The samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectra and X-ray diffraction (XRD). As anode of lithium ion batteries (LIBs), it exhibits excellent reversible specific capacity of 1753 mAh g−1 at 0.1 A g-1 after 200 cycles. The reversible capacity can maintain at 1322 mAh g−1 after 500 cycles at 2 A g−1. At the same time, all results indicate remarkable cycle stability and rate performance as anode materials. Furthermore, this study demonstrates an economical, clean and facile strategy to synthesize N/G nanosheets from cheap chemicals with excellent electrochemical performance in LIBs. 相似文献
999.
《International Journal of Hydrogen Energy》2019,44(59):31153-31159
Li-air batteries (LABs) operated in ambient air containing moisture and CO2 highly desire the oxygen electrodes to have capability of Li2CO3 and LiOH decomposition and electrochemical stability. Here we report the application of a stable non-carbon based oxygen electrode based on boron carbide supported ruthenium (Ru/B4C) for ambient LABs. LABs using Ru/B4C deliver a discharge capacity of 2689 mA h g−1 and voltage plateaus of 2.7 V and 3.8 V for discharge and charge process, respectively at 0.1 mA cm−2, which are comparable to those for Ru/B4C-based Li–O2 battery (2796 mA h g−1, 2.8 V and 3.7 V, respectively). Under limited capacity of 300 mA h g−1, LAB exhibits 45 stable cycles, close to the 50 cycles for its Li–O2 battery counterpart. The typical product for the first discharge for LAB is the mixture of Li2CO3 and Li2O2 with relative content ratio of 62:38, which cannot be detected after the first charge. The non-carbon based Ru/B4C oxygen electrode provides a promising approach for the stable operation of LABs in ambient air. 相似文献
1000.
Mangmang Shi Yinglin Yan Yiqi Wei Yiming Zou Qijiu Deng Juan Wang Rong Yang Yunhua Xu Tong Han 《国际能源研究杂志》2019,43(13):7614-7626
Carbon aerogel (CA), possessing abundant pore structures and excellent electrical conductivity, have been utilized as conductive sulfur hosts for lithium‐sulfur (Li‐S) batteries. However, a serious shuttle effect resulted from polysulfide ions has not been effectively suppressed yet due to the weak absorption nature of CA, resulting in rapid decay of capacity as the cycle number increases. Herein, ultrafine (~3 nm) gadolinium oxide (Gd2O3) nanoparticles (with upper redox potential of ~ 1.58 V versus Li+/Li) are uniformly in‐situ integrated with CA through directly sol‐gel polymerization and high‐temperature carbonization. The Gd2O3 modified CA composites (named as Gdx‐CA, where x means molar ratio of Gd2O3 nanoparticles to carbon) are incorporated with S. Then, the products (S/Gdx‐CA) are acted as sulfur host materials for Li‐S batteries. The results demonstrate that adding ultrafine Gd2O3 nanoparticles can dramatically improve the electrochemical properties of the composite cathodes. The S/Gd2‐CA electrode (loading with 58.9 wt% of S) possesses the best electrochemical properties, including a high initial capacity of 1210 mAh g?1 and a relatively high capacity of 555 mAh g?1 after 50 cycles at 0.1 C. It is noteworthy that the performance of long‐term cycle (350 cycles) for the S/Gd2‐CA (317 mAh g?1 after 100 cycles and 233 mAh g?1 after 350 cycles at 1 C) is improved significantly than that of S/CA (150 mAh g?1 after 150 cycles at 1 C). Overall, the enhancement of electrochemical performances can be due to the strong polar nature of the ultrafine Gd2O3 nanoparticles, which provide strong adsorption sites to immobilize S and polysulfide. Furthermore, the Gd2O3 nanoparticles present a catalytic effect. Our research suggests that adding Gd2O3 nanoparticles into S/CA composite cathode is an effective and novelty method for improving the electrochemical performances of Li‐S batteries. 相似文献