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A variety of disubstituted (double-comb) polysiloxane polymers have been prepared containing linear, branched, and cyclic oligoethyleneoxide units, –(OCH2CH2)n–, in the side chains and as part of the siloxane backbone. Copolymers, using mixtures of linear ethylene oxide side chains, were also synthesized. These polymers were doped with LiN(SO2CF3)2 (LiTFSI, 1) and conductivities of the polymer-salt complexes were determined as a function of temperature and doping level. The maximum conductivity of these polymers at 25 ° C was 2.99 ×10–4, for a copolymer containing equimolar amounts of side chains with n = 5 and 6. 相似文献
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Xingang Kong Jiarui Zhang Jianfeng Huang Jiayin Li Yi Qin Ting Zhao Qi Feng 《中国化学快报》2019,30(3):771-774
SnNb2O6 and Sn2Nb2O7 nanosheets were synthetized via microwave assisted hydrothermal method, and innovatively employed as anode materials for lithium-ion battery. Compared with Sn2Nb2O7 and the previously reported pure Sn-based anode materials, the SnNb2O6 electrode exhibited outstanding cycling performance. 相似文献
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Min Jiang Junliang Chen Dr. Yuanyuan Ma Prof. Wei Luo Prof. Jianping Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(36):9320-9327
Recently, the frequency of combining MXene, which has unique properties such as metal-level conductivity and large specific surface area, with silicon to achieve excellent electrochemical performance has increased considerably. There is no doubt that the introduction of MXene can improve the conductivity of silicon and the cycling stability of electrodes after elaborate structure design. However, most exhaustive contacts can only improve the electrode conductivity on the plane. Herein, a MXene@Si/CNTs (HIEN-MSC) composite with hierarchical interpenetrating electroconductive networks has been synthesized by electrostatic self-assembly. In this process, the CNTs are first combined with silicon nanoparticles and then assembled with MXene nanosheets. Inserting CNTs into silicon nanoparticles can not only reduce the latter‘s agglomeration, but also immobilizes them on the three-dimensional conductive framework composed of CNTs and MXene nanosheets. Therefore, the HIEN-MSC electrode shows superior rate performance (high reversible capacity of 280 mA h−1 even tested at 10 A g−1), cycling stability (stable reversible capacity of 547 mA h g−1 after 200 cycles at 1 A g−1) and applicability (a high reversible capacity of 101 mA h g−1 after 50 cycles when assembled with NCM622 into a full cell). These results may provide new insights for other electrodes with excellent rate performance and long-cycle stability. 相似文献
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Hüseyin Göktepe 《中国化学会会志》2013,60(2):218-222
Dy doping and carbon coating are adopted to synthesize a LiFePO4 cathode material in a simple solution environment. The samples were characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). Their electrochemical properties were investigated by cyclic voltammetry (CV) and galvanostatic charge‐discharge tests. An initial discharge capacity of 153 mAh/g was achieved for the LiDy0.02Fe0.98PO4/C composite cathode with a rate of 0.1 C. In addition the electronic conductivity of Dy doped LiFePO4/C was enhanced to 1.9 × 10?2 Scm?1. The results suggest that the improvement of the electrochemical properties are attributed to the dysprosium doping and carbon coating which facilitates the phase transformation between triphylite and heterosite during cycling. XRD data indicate that doping did not destroy the lattice structure of LiFePO4. To evaluate the effect of Dy substitution, cyclic voltammetry was used at room temperature. prepared. From Cv measurement a more symmetric curve with smaller interval between the cathodic and anodic peak current was obtained by Dy substitution. This denoted a decreasing of polarization with Dy substitution, which illustrated an enhancement of electrochemical performances. 相似文献
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Zirui Song Kangyu Zou Xuhuan Xiao Xinglan Deng Shuo Li Prof. Dr. Hongshuai Hou Prof. Dr. Xiaoming Lou Prof. Dr. Guoqiang Zou Prof. Dr. Xiaobo Ji 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(65):16082-16092
Nowadays sodium-based energy storage systems (Na-based ESSs) have been widely researched as it possesses the possibility to replace traditional energy storage media to become next generation energy storage system. However, due to the irreversible loss of sodium ions in the first cycle, development of Na-based ESSs is limited. Presodiation, as a strategy of adding excess sodium ions to the system in advance, accomplishes the enhancement of electrochemical performance. In this minireview, different presodiation strategies applied in sodium-based energy storage systems will be summarized in detail, their functions and corresponding mechanisms will be discussed as well. Furthermore, the current novel application of presodiation method in other aspects of Na-based ESSs will be mentioned additionally. At last, in the view of present research status of presodiation, issues that can be mitigated are put forward and guidelines are given on how to deliberate in-depth presodiation technology in the future, dedicating to promote the further development of Na-based ESSs. 相似文献
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