WO3/LiV3O8用于电控离子交换选择性提锂

Selective Lithium Extraction by Electrochemically Switched Ion Exchange Using WO3/LiV3O8

中文关键词:  WO3/LiV3O8  锂离子  电控离子交换  吸附容量  选择性分离

英文关键词:WO3/LiV3O8  Lithium ion  ESIX  Adsorption capacity  Selective separation

中文摘要:

      首先通过水热合成制备了六方隧道结构的WO3，然后再通过两步法将LiV3O8与WO3进行复合，制备成WO3/LiV3O8复合材料。随后采用XRD、SEM、EDS等手段对该复合材料进行了结构表征，并考察了不同复合比例的WO3/LiV3O8电控离子交换(ESIX)性能。实验结果表明，LiV3O8与WO3成功复合，其中WO3 (10%)/LiV3O8 的电化学性能最佳。将WO3 (10%)/LiV3O8 涂覆到预处理好的碳纸上，制备成电活性功能膜，采用ESIX技术在30 mg/L的含Li+溶液中对Li+进行电化学吸附，在电位为-1.0 V(vs. SCE)时吸附容量最大，为14.2 mg·g-1。在三种离子浓度均为0.015 mol/L 的Li+、Mg2+、K+混合溶液中测试了该材料的选择性，Li+/Mg2+和Li+/K+的选择性系数分别为15.88和52.23，五次吸附-脱附循环后，Li+的吸附容量仍能保持初始容量的87.8%。WO3/LiV3O8对Li+吸附表现出较高的吸附选择性，且复合材料具有一定的可重复使用性。

英文摘要:

      In this study， WO3 with hexagonal tunneling structure was firstly prepared by hydrothermal method， and then LiV3O8 was compounded with WO3 by two-step method to prepare WO3/LiV3O8 composites. The composites were subsequently structurally characterized by XRD， SEM and EDS， and the electronically switched ion exchange (ESIX) performances of WO3/LiV3O8 under the different ratios of WO3 were investigated. The experimental results show that LiV3O8 and WO3 were successfully compounded， and WO3 (10%)/LiV3O8 had the best electrochemical performance. WO3 (10%)/LiV3O8 was coated on the pretreated carbon paper to prepare the electroactive functional film. The ESIX technology was used to adsorb Li+ in 30 mg/L Li+ solution， and the maximum adsorption capacity was 14.2 mg·g-1 at a potential of-1.0 V (vs. SCE). The selectivity of this material was tested in a mixed solution of 0.015 mol/L Li+， Mg2+ and K+. The selectivity coefficient of Li+/Mg2+ and Li+/K+ was 15.88 and 52.23， respectively. After five adsorption-desorption cycles， the Li+ adsorption capacity maintained 87.8% of the initial capacity. In summary， WO3/LiV3O8 exhibited high adsorption selectivity for Li+ and the composites were somewhat reusable.