Department of Chemistry University of Iowa , Iowa City , Iowa 52242 , United States.
Department of Chemistry University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States.
Environ Sci Technol. 2018 May 15;52(10):5792-5802. doi: 10.1021/acs.est.8b00054. Epub 2018 Apr 24.
The rapid increase in use of Li-ion batteries in portable electronics has created a pressing need to understand the environmental impact and long-term fate of electonic waste (e-waste) products such as heavy and/or reactive metals. The type of e-waste that we focus on here are the complex metal oxide nanomaterials that compose Li-ion battery cathodes. While in operation the complex metal oxides are in a hermetically sealed container. However, at the end of life, improper disposal can cause structural transformations such as dissolution and metal leaching, resulting in a significant exposure risk to the surrounding environment. The transformations that occur between operational to environmental settings gives rise to a stark knowledge gap between macroscopic design and molecular-level behavior. In this study we use theory and modeling to describe and explain previously published experimental data for cation release from Li(NiMnCo)O (NMC) nanoparticles in an aqueous environment ( Chem. Mater. 2016 (28) 1092-1100). To better understand the transformations that may occur when this material is exposed to the environment, we compute the free energy of surface dissolution, Δ G, from the complex metal oxide NMC for a range of surface terminations and pH.
锂离子电池在便携式电子产品中的应用迅速增加，这使得人们迫切需要了解电子废物（电子垃圾）产品的环境影响和长期命运，如重金属和/或反应性金属。我们在这里关注的电子垃圾类型是构成锂离子电池正极的复杂金属氧化物纳米材料。在运行过程中，复杂的金属氧化物处于密封的容器中。然而，在使用寿命结束时，不当处理可能会导致结构转化，如溶解和金属浸出，从而对周围环境造成重大暴露风险。从运行到环境设置的转变，导致宏观设计和分子水平行为之间存在明显的知识差距。在这项研究中，我们使用理论和建模来描述和解释之前发表的关于阳离子在水溶液中从 Li（NiMnCo）O（NMC）纳米颗粒中释放的实验数据（Chem. Mater. 2016（28）1092-1100）。为了更好地理解当这种材料暴露于环境时可能发生的转变，我们计算了具有不同表面终止和 pH 值的复杂金属氧化物 NMC 的表面溶解自由能 ΔG。
