涂玉鑫, 李田玉, 李吉青, 陈佳煌, 关利聪, 王瑞祥, 徐志峰, 刘志楼. 固相法合成钴掺杂锰系锂离子筛的吸附性能[J]. 工程科学学报. DOI: 10.13374/j.issn2095-9389.2024.05.10.004
引用本文: 涂玉鑫, 李田玉, 李吉青, 陈佳煌, 关利聪, 王瑞祥, 徐志峰, 刘志楼. 固相法合成钴掺杂锰系锂离子筛的吸附性能[J]. 工程科学学报. DOI: 10.13374/j.issn2095-9389.2024.05.10.004
TU Yuxin, LI Tianyu, LI Jiqing, CHEN Jiahuang, GUAN Licong, WANG Ruixiang, XU Zhifeng, LIU Zhilou. Lithium adsorption performance of Co-doped manganese-based lithium-ion sieves prepared via solid-phase synthesis[J]. Chinese Journal of Engineering. DOI: 10.13374/j.issn2095-9389.2024.05.10.004
Citation: TU Yuxin, LI Tianyu, LI Jiqing, CHEN Jiahuang, GUAN Licong, WANG Ruixiang, XU Zhifeng, LIU Zhilou. Lithium adsorption performance of Co-doped manganese-based lithium-ion sieves prepared via solid-phase synthesis[J]. Chinese Journal of Engineering. DOI: 10.13374/j.issn2095-9389.2024.05.10.004

固相法合成钴掺杂锰系锂离子筛的吸附性能

Lithium adsorption performance of Co-doped manganese-based lithium-ion sieves prepared via solid-phase synthesis

  • 摘要: 随着5G/6G通信、新能源汽车、锂电池产业的快速发展,近年来对锂化合物(尤其是Li2CO3)的需求急剧增加,许多国家将锂视为战略矿产资源. 目前从锂沉淀母液中提取锂受到了极大的关注. 锰系离子筛(LMO)是一种具有广泛应用前景的吸附剂,可实现复杂溶液中锂的高效回收. 但LMO在酸洗解吸过程中存在锰溶损严重的难题,会降低吸附性能和循环性能. 针对上述问题,本研究提出引入Co3+掺杂降低LMO锰溶解损失的策略,制备了钴掺杂锰系离子筛(LCMO). 采用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)等方法对不同煅烧温度和焙烧时间下制备的LCMO进行表征分析. 表征结果表明,Co掺杂对LMO的尖晶石结构没有影响,并且Co最佳掺杂摩尔分数为5%,此时离子筛前驱体中Mn3+的原子分数从未掺杂的9.67%降低到3.63%,对应的锂吸附容量从39.299 mg·g−1显著增加到41.708 mg·g−1,锰溶损也从1.288%显著降低至0.837%,大大地增加了锰系离子筛的实际应用可能性. 制备的摩尔分数为5%Co掺杂的离子筛(LCMO-5%)具有良好的循环性能,Li+的吸附能力在5次循环后仍然保持在81%以上. 在模拟的锂沉淀母液中,Li/Na和Li/K之间的分离系数分别为74.655和64.547,这证明了LCMO-5%能有效地从高Na+、K+溶液中吸附分离Li+. 因此,LCMO-5%离子筛具有从锂沉淀母液中提取Li+的应用前景.

     

    Abstract: With the rapid development of 5G/6G communications, new energy vehicles, and lithium battery industries, the demand for lithium compounds (especially Li2CO3) has dramatically increased in recent years. Many countries have regarded lithium as a strategic mineral resource. Lithium is mainly found in liquid mineral resources around the world, and the extraction of lithium from the mother liquor of lithium precipitates has thus garnered significant attention. The main methods for recovering lithium from solutions include membrane separation, solvent extraction, electrochemistry, and adsorption. Among them, the adsorption method is one of the most promising. The key to successful adsorption technology is the construction of high-performance adsorbents with high adsorption capacity, high ionic selectivity, and high structural stability. The manganese-ion sieve named as LMO, is a promising adsorbent that has been widely studied because of its good chemical stability, excellent adsorption properties, and outstanding ion selectivity for lithium extraction. However, its inherent dissolution loss greatly restricts its practical application. To reduce the dissolution loss of manganese-ion sieves, several strategies, such as adjusting the synthesis process, composition optimization, ion doping, and surface modification, were adopted. This study introduces Co3+ doping to mitigate manganese loss in LMO, resulting in the preparation of cobalt-doped manganese-based ion sieves (LCMO). LCMOs prepared at various calcination temperatures and times were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy, and X-ray photoelectron spectroscopy (XPS). The XRD characterization results indicate that Co doping has no effect on the spinel structure of LMO. The SEM results confirmed the successful doping and uniform Co distribution in LCMO-5%. The XPS results show that a Co doping molar fraction of 5% can reduce the content of Mn3+ from 9.67% in the undoped precursor to 3.63%, which may be because the partial substitution of Mn3+ by Co3+ reduces the proportion of Mn3+. The lithium adsorption capacity increased from 39.299 to 41.708 mg·g−1, and the manganese dissolution significantly decreased from 1.288% to 0.84%. The performance improvement of the LCMO greatly promotes the practical application of manganese-based ion sieves. The prepared 5% molar fraction of the Co-doped ion sieve (LCMO-5%) exhibited excellent cycling performance, and the adsorption efficiency of Li+ remained above 81% after five cycles. In the simulated lithium precipitation mother liquor, the separation coefficients of Li/Na and Li/K were 74.655 and 64.547, respectively, indicating that LCMO-5% effectively adsorbed Li+ from solutions containing high concentrations of Na+ and K+. Therefore, the LCMO-5% ion sieve exhibits outstanding application prospects for Li+ extraction from liquid lithium resources.

     

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