The overall performance of lithium-ion batteries （LIBs） is closely related to the interphase between the electrode materials and electrolytes. During LIB operation, electrolytes may decompose on the surface of elect...The overall performance of lithium-ion batteries （LIBs） is closely related to the interphase between the electrode materials and electrolytes. During LIB operation, electrolytes may decompose on the surface of electrode materials, forming a solid electrolyte interphase （SEI） layer. Ideally, the SEI layer should ensure reversible lithium-ion intercalation in the electrodes and suppress interfacial interactions. However, the chemical and mechanical stabilities of the SEI layer are not usually able to meet these requirements. Alternatively, tremendous efforts have been devoted to engineering the surface of electrode materials with an artificial interphase, which shows great promise in improving the electrochemical performance. Herein, we present a comprehensive summary of the state-of-the-art knowledge on this topic. The effects of the arrifidal interphase on the electrochemical performance of the electrode materials are discussed in detail. In particular, we highlight the importance of three functions of artificial interphases, including inhibiting electrolyte decomposition, protecting the electrodes from corrosion, and accommodatinz electrode volume chanzes.展开更多
The 100 crystal-oriented silicon micropillar array platforms were prepared by microfabrication processes for the purpose of electrolyte additive identification. The silicon micropillar array platform was used for the ...The 100 crystal-oriented silicon micropillar array platforms were prepared by microfabrication processes for the purpose of electrolyte additive identification. The silicon micropillar array platform was used for the study of fluorinated vinyl carbonate(FEC), vinyl ethylene carbonate(VEC), ethylene sulfite(ES), and vinyl carbonate(VC) electrolyte additives in the LiPF_6 dissolved in a mixture of ethylene carbonate and diethyl carbonate electrolyte system using charge/discharge cycles, electrochemical impedance spectroscopy, cyclic voltammetry, scanning electron microscopy, and x-ray photoelectron spectroscopy. The results show that the silicon pillar morphology displays cross-shaped expansion after lithiation/delithiation, the inorganic lithium salt keeps the silicon pillar morphology intact, and the organic lithium salt content promotes a rougher silicon pillar surface. The presence of poly-(VC) components on the surface of FEC and VC electrodes allows the silicon pillar to accommodate greater volume expansion while remaining intact. This work provides a standard, fast, and effective test method for the performance analysis of electrolyte additives and provides guidance for the development of new electrolyte additives.展开更多
文摘The overall performance of lithium-ion batteries （LIBs） is closely related to the interphase between the electrode materials and electrolytes. During LIB operation, electrolytes may decompose on the surface of electrode materials, forming a solid electrolyte interphase （SEI） layer. Ideally, the SEI layer should ensure reversible lithium-ion intercalation in the electrodes and suppress interfacial interactions. However, the chemical and mechanical stabilities of the SEI layer are not usually able to meet these requirements. Alternatively, tremendous efforts have been devoted to engineering the surface of electrode materials with an artificial interphase, which shows great promise in improving the electrochemical performance. Herein, we present a comprehensive summary of the state-of-the-art knowledge on this topic. The effects of the arrifidal interphase on the electrochemical performance of the electrode materials are discussed in detail. In particular, we highlight the importance of three functions of artificial interphases, including inhibiting electrolyte decomposition, protecting the electrodes from corrosion, and accommodatinz electrode volume chanzes.
基金supported by the National Key R&D Program of China (Grant Nos. 2016YFB0100500 and 2016YFB0100100)the National Natural Science Foundation of China (Grant Nos. 11674387, 11574385, 22005332, 115674368, and 62065005)。
文摘The 100 crystal-oriented silicon micropillar array platforms were prepared by microfabrication processes for the purpose of electrolyte additive identification. The silicon micropillar array platform was used for the study of fluorinated vinyl carbonate(FEC), vinyl ethylene carbonate(VEC), ethylene sulfite(ES), and vinyl carbonate(VC) electrolyte additives in the LiPF_6 dissolved in a mixture of ethylene carbonate and diethyl carbonate electrolyte system using charge/discharge cycles, electrochemical impedance spectroscopy, cyclic voltammetry, scanning electron microscopy, and x-ray photoelectron spectroscopy. The results show that the silicon pillar morphology displays cross-shaped expansion after lithiation/delithiation, the inorganic lithium salt keeps the silicon pillar morphology intact, and the organic lithium salt content promotes a rougher silicon pillar surface. The presence of poly-(VC) components on the surface of FEC and VC electrodes allows the silicon pillar to accommodate greater volume expansion while remaining intact. This work provides a standard, fast, and effective test method for the performance analysis of electrolyte additives and provides guidance for the development of new electrolyte additives.
文摘主要介绍了微米硅、多孔微米硅以及经修饰后的硅-氧化钴电极材料性能。以质量分数12%的氧化钴修饰多孔硅,首次与第二次放电电容量分别为3 590m Ah·g^(–1)和2 679m Ah·g^(–1),其放电电容量衰退率为25.4%。与没有修饰过的微米硅(2 281 m Ah·g^(–1)和555 m Ah·g^(–1))相比,效果明显提升,并且在之后的多次充放电中,也有很大提高。分析结果表明,微米多孔硅减缓了硅在充放电时的体积膨胀;被披覆氧化钴稳定了固态电解质层,进而提高了硅材料在锂离子电池中充放电循环稳定性。
