Abstract：
In this study, a three-step strategy including electrochemical cathode deposition, self-oxidation, and hydrothermal reaction is applied to prepare the LiMn2 O4 nanosheets on carbon cloth (LMOns@CC) as a binder-free cathode in a hybrid capacitive deionization (CDI) cell for selectively extracting lithium from salt-lake brine. The binder-free LMOns@CC electrodes are constructed from dozens of 2D LiMn2 O4 nanosheets on carbon cloth substrates, resulting in a uniform 2D array of highly ordered nanosheets with hierarchical nanostructure. The charge/discharge process of the LMOns@CC electrode demonstrates that visible redox peaks and high pseudocapacitive contribution rates endow the LMOns@CC cathode with a maximum Li+ ion electrosorption capacity of 4.71 mmol g-1 at 1.2 V. Moreover, the LMOns@CC electrode performs outstanding cycling stability with a high-capacity retention rate of 97.4% and a manganese mass dissolution rate of 0.35% over ten absorption-desorption cycles. The density functional theory (DFT) theoretical calculations verify that the Li+ selectivity of the LMOns@CC electrode is attributed to the greater adsorption energy of Li+ ions than other ions. Finally, the selective extraction performance of Li+ ions in natural Tibet salt lake brine reveals that the LMOns@CC has selectivity ( α Mg 2 + Li + $\\alpha _{{\\mathrm{Mg}}^{2 + }}^{{\\mathrm{Li}}^ + }$ = 7.48) and excellent cycling stability (100 cycles), which would make it a candidate electrode for lithium extraction from salt lakes.
摘要：
在这项研究中,包括电化学阴极沉积的三步策略，自氧化,并应用水热反应在碳布（LMOns@CC）上制备LiMn2O4纳米片，作为混合电容去离子（CDI）电池中的无粘合剂阴极，用于从盐湖盐水中选择性提取锂。无粘合剂的LMOns@CC电极由碳布基底上的数十个2DLiMn2O4纳米片构成，导致具有分层纳米结构的高度有序纳米片的均匀2D阵列。LMOns@CC电极的充电/放电过程表明，可见的氧化还原峰和高伪电容贡献率赋予LMOns@CC阴极在1.2V时的最大Li离子电吸附容量为4.71mmolg-1。LMOns@CC电极具有出色的循环稳定性，在10次吸收-解吸循环中具有97.4%的高容量保留率和0.35%的锰质量溶解率。密度泛函理论（DFT）的理论计算验证了LMOns@CC电极的Li选择性归因于Li离子比其他离子更大的吸附能。最后,对天然西藏盐湖卤水中Li+离子的选择性萃取性能表明，LMOns@CC具有选择性(αMg2+Li+$\\alpha_{{\\mathrm{Mg}}^{2+}}^{\\mathrm{Li}}^+}$=7.48)和优异的循环稳定性(100次循环)，这将使其成为从盐湖中提取锂的候选电极。
