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Operando Raman Spectroscopy and Synchrotron X-ray Diffraction of Lithiation/Delithiation in Silicon Nanoparticle Anodes
ACS Nano ( IF 15.8 ) Pub Date : 2017-11-09 00:00:00 , DOI: 10.1021/acsnano.7b05796 Samuel Tardif 1 , Ekaterina Pavlenko 2 , Lucille Quazuguel 2 , Maxime Boniface 1 , Manuel Maréchal 2 , Jean-Sébastien Micha 2 , Laurent Gonon 2 , Vincent Mareau 2 , Gérard Gebel 3 , Pascale Bayle-Guillemaud 1 , François Rieutord 1 , Sandrine Lyonnard 2
ACS Nano ( IF 15.8 ) Pub Date : 2017-11-09 00:00:00 , DOI: 10.1021/acsnano.7b05796 Samuel Tardif 1 , Ekaterina Pavlenko 2 , Lucille Quazuguel 2 , Maxime Boniface 1 , Manuel Maréchal 2 , Jean-Sébastien Micha 2 , Laurent Gonon 2 , Vincent Mareau 2 , Gérard Gebel 3 , Pascale Bayle-Guillemaud 1 , François Rieutord 1 , Sandrine Lyonnard 2
Affiliation
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Operando Raman spectroscopy and synchrotron X-ray diffraction were combined to probe the evolution of strain in Li-ion battery anodes made of crystalline silicon nanoparticles. The internal structure of the nanoparticles during two discharge/charge cycles was evaluated by analyzing the intensity and position of Si diffraction peaks and Raman TO–LO phonons. Lithiation/delithiation of the silicon under limited capacity conditions triggers the formation of “crystalline core–amorphous shell” particles, which we evidenced as a stepwise decrease in core size, as well as sequences of compressive/tensile strain due to the stress applied by the shell. In particular, we showed that different sequences occur in the first and the second cycle, due to different lithiation processes. We further evidenced critical experimental conditions for accurate operando Raman spectroscopy measurements due to the different heat conductivity of lithiated and delithiated Si. Values of the stress extracted from both operando XRD and Raman are in excellent agreement. Long-term ex situ measurements confirmed the continuous increase of the internal compressive strain, unfavorable to the Si lithiation and contributing to the capacity fading. Finally, a simple mechanical model was used to estimate the sub-nanometer thickness of the interfacial shell applying the stress on the crystalline core. Our complete operando diagnosis of the strain and stress in SiNPs provides both a detailed scenario of the mechanical consequences of lithiation/delithiation in SiNP and also experimental values that are much needed for the benchmarking of theoretical models and for the further rational design of SiNP-based electrodes.
中文翻译：
硅纳米粒子阳极中锂化/脱锂的Operando拉曼光谱和同步X射线衍射
Operando拉曼光谱和同步加速器X射线衍射相结合，以探测由晶体硅纳米粒子制成的锂离子电池阳极中应变的演变。通过分析Si衍射峰和拉曼TO–LO声子的强度和位置，评估了两个放电/充电周期中纳米颗粒的内部结构。硅在有限容量条件下的锂化/脱锂会触发“结晶核-无定形壳”颗粒的形成，我们证明这是核尺寸逐步减小，以及由于应力作用而产生的压缩/拉伸应变序列。壳。尤其是，我们表明，由于锂化工艺的不同，在第一和第二个循环中会出现不同的顺序。我们进一步证明了关键实验条件的准确性operando拉曼光谱测量由于锂化和脱锂Si的不同热导率。从XRD手术和拉曼手术中提取的压力值非常吻合。长期的异位测量证实了内部压缩应变的持续增加，这不利于Si的锂化，并导致容量衰减。最后，使用简单的力学模型来估算应力，将应力施加到结晶核上，从而估算界面壳的亚纳米厚度。我们完整的操作 对SiNPs中的应变和应力的诊断不仅提供了SiNP中锂化/脱锂的机械后果的详细情况，而且还提供了用于理论模型基准测试和进一步合理设计基于SiNP的电极所需的实验值。
更新日期：2017-11-09
中文翻译：
硅纳米粒子阳极中锂化/脱锂的Operando拉曼光谱和同步X射线衍射
Operando拉曼光谱和同步加速器X射线衍射相结合，以探测由晶体硅纳米粒子制成的锂离子电池阳极中应变的演变。通过分析Si衍射峰和拉曼TO–LO声子的强度和位置，评估了两个放电/充电周期中纳米颗粒的内部结构。硅在有限容量条件下的锂化/脱锂会触发“结晶核-无定形壳”颗粒的形成，我们证明这是核尺寸逐步减小，以及由于应力作用而产生的压缩/拉伸应变序列。壳。尤其是，我们表明，由于锂化工艺的不同，在第一和第二个循环中会出现不同的顺序。我们进一步证明了关键实验条件的准确性operando拉曼光谱测量由于锂化和脱锂Si的不同热导率。从XRD手术和拉曼手术中提取的压力值非常吻合。长期的异位测量证实了内部压缩应变的持续增加，这不利于Si的锂化，并导致容量衰减。最后，使用简单的力学模型来估算应力，将应力施加到结晶核上，从而估算界面壳的亚纳米厚度。我们完整的操作 对SiNPs中的应变和应力的诊断不仅提供了SiNP中锂化/脱锂的机械后果的详细情况，而且还提供了用于理论模型基准测试和进一步合理设计基于SiNP的电极所需的实验值。
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