Norberg Andreas Nicolai, Wagner Nils Peter, Kaland Henning, Vullum-Bruer Fride, Svensson Ann Mari
Department of Materials Science and Engineering, Norwegian University of Science and Technology, NTNU Sem Sælands Vei 12, Realfagbygget K2-132 7034 Trondheim Norway
Department of Sustainable Energy Technology, SINTEF Industry Strindveien 4 7034 Trondheim Norway
RSC Adv. 2019 Dec 12;9(70):41228-41239. doi: 10.1039/c9ra07271c. eCollection 2019 Dec 9.
In spite of its insulating nature, SiO may be utilized as active anode material for Li-ion batteries. Synthetic SiO will typically require sophisticated synthesis and/or activation procedures in order to obtain a satisfactory performance. Here, we report on diatom frustules as active anode material without the need for extensive activation procedures. These are composed primarily of silica, exhibiting sophisticated porous structures. Various means of optimizing the performance were investigated. These included carbon coating, the addition of fluoroethylene carbonate (FEC) and vinylene carbonate (VC) to the carbonate-based electrolyte, as well as activation by an initial potentiostatic hold step. The highest capacity (723 mA h g) was obtained with composite electrodes with pristine diatom frustules and conventional carbon black as additive, with the capacity still increasing after 50 cycles. The capacity was around 624 mA h g after subtraction of the contributions from the carbon black. Carbon coated diatom frustules showed a slightly lower but stable capacity after 50 cycles (600 mA h g after subtraction of contributions from the carbon coating and the carbon black). By the use of electrochemical characterization methods, as well as studies, differences in reaction mechanisms could be identified and attributed to the operating and processing parameters.
尽管二氧化硅具有绝缘性，但它仍可作为锂离子电池的活性阳极材料。合成二氧化硅通常需要复杂的合成和/或活化程序才能获得令人满意的性能。在此，我们报道了硅藻壳作为活性阳极材料，无需进行广泛的活化程序。硅藻壳主要由二氧化硅组成，具有复杂的多孔结构。我们研究了各种优化性能的方法。这些方法包括碳涂层、向碳酸盐基电解质中添加氟代碳酸乙烯酯（FEC）和碳酸亚乙烯酯（VC），以及通过初始恒电位保持步骤进行活化。以原始硅藻壳和传统炭黑作为添加剂的复合电极获得了最高容量（723 mA h/g），在50次循环后容量仍在增加。扣除炭黑的贡献后，容量约为624 mA h/g。碳包覆硅藻壳在50次循环后显示出略低但稳定的容量（扣除碳涂层和炭黑的贡献后为600 mA h/g）。通过使用电化学表征方法以及研究，可以识别反应机制的差异并将其归因于操作和加工参数。
