Silicon has been the subject of an extensive research effort aimed at developing new anode materials for lithium ion batteries due to its large specific and volumetric capacity. However, commercial use is limited by a number of degradation problems, many of which are related to the large volume change the material undergoes during cycling in combination with limited lithium-diffusivity. Silicon rich silicon oxides (SiOx), which converts into active silicon and inactive lithium oxide during the initial lithiation, have attracted some attention as a possible solution to these issues. In this work we present an investigation of silicon rich amorphous silicon nitride (a-SiNx) as an alternative convertible anode material. Amorphous SiN0.89 thin films deposited by plasma enhanced chemical vapour deposition show reversible reactions with lithium when cycled between 0.05 and 1.0 V vs. Li+/Li. This material delivers a reversible capacity of approximately 1,200 mAh/g and exhibits excellent cycling stability, with 41 nm a-SiN0.89 thin film electrodes showing negligible capacity degradation over more than 2,400 cycles.
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机译:硅由于其大的比容和体积容量而一直致力于开发用于锂离子电池的新型负极材料的广泛研究工作的主题。然而,商业用途受到许多降解问题的限制,其中许多问题与材料在循环过程中经历的大体积变化以及有限的锂扩散性有关。富硅氧化硅(SiOx)在初始锂化过程中会转变为活性硅和惰性氧化锂,作为解决这些问题的一种可能解决方案引起了人们的关注。在这项工作中,我们提出了对富硅非晶氮化硅(a-SiNx)作为可转换阳极材料的研究。与Li + sup> / Li相比,通过等离子增强化学气相沉积法沉积的非晶SiN0.89薄膜在0.05和1.0 V之间循环时与锂发生可逆反应。这种材料的可逆容量约为1,200 mAh / g,并具有出色的循环稳定性,其中41μnm的a-SiN0.89薄膜电极在超过2,400个循环中显示出可忽略的容量下降。
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