Compositional control of precipitate precursors for lithium-ion battery active materials: role of solution equilibrium and precipitation rate
Compositional control of precipitate precursors for lithium-ion battery active materials: role of solution equilibrium and precipitation rate
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DOI：
10.1039/c7ta03653a
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发表时间：
2017-07
影响因子：
--
通讯作者：
Hong Dong;Gary M. Koenig
中科院分区：
文献类型：
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作者：
Hong Dong;Gary M. Koenig
多组分过渡金属氧化物是最成功的锂离子电池阴极材料之一，并且许多先前的报告已经描述了活性材料的最终电化学性能对详细组成和加工的敏感性。前体模板的共沉淀是合成这些过渡金属氧化物阴极材料的流行的、可扩展的途径，因为过渡金属在颗粒内的均匀混合以及由前体提供的形态控制。然而，前体组合物与进料条件的偏差是一个挑战，在以前的研究中通常没有报道过。以高压尖晶石LiMn1.5Ni0.5O4为例，我们在这项研究中表明，在某些条件下，共沉淀引起的成分偏差可能是显着的，影响煅烧后的最终材料结构和电化学性能。本文的研究提供了对前体上的沉淀物形成期间过渡金属的溶液平衡和沉淀速率的作用以及因此最终活性材料组合物的见解。这种知识对于合理地预测和调整经由共沉淀以高水平的准确度合成的多组分电池前体组合物是必要的。
Multicomponent transition metal oxides are among the most successful lithium-ion battery cathode materials, and many previous reports have described the sensitivity of final electrochemical performance of the active materials to the detailed composition and processing. Coprecipitation of a precursor template is a popular, scalable route to synthesize these transition metal oxide cathode materials because of the homogeneous mixing of the transition metals within the particles, and the morphology control provided by the precursors. However, the deviation of the precursor composition from feed conditions is a challenge that has generally not been reported in previous studies. Using a target final material of the high voltage spinel LiMn1.5Ni0.5O4 as an example, we show in this study that the compositional deviation caused by coprecipitation can be significant under certain conditions, impacting the calcined final material structure and electrochemical properties. The study herein provides insights into the role of solution equilibrium and rate of precipitation of the transition metals during precipitate formation on precursor, and thus final active material, composition. Such knowledge is necessary to rationally predict and tune multicomponent battery precursor compositions synthesized via coprecipitation with high levels of accuracy.