PDF(Pubmed)
Abstract：
The high demand for lithium (Li) relates to clean, renewable storage devices and the advent of electric vehicles (EVs). The extraction of Li ions from aqueous media calls for efficient adsorbent materials with various characteristics, such as good adsorption capacity, good selectivity, easy isolation of the Li-loaded adsorbents, and good recovery of the adsorbed Li ions. The widespread use of metal-based adsorbent materials for Li ions extraction relates to various factors: (i) the ease of preparation via inexpensive and facile templation techniques, (ii) excellent selectivity for Li ions in a matrix, (iii) high recovery of the adsorbed ions, and (iv) good cycling performance of the adsorbents. However, the use of nano-sized metal-based Lithium-ion sieves (LISs) is limited due to challenges associated with isolating the loaded adsorbent material from the aqueous media. The adsorbent granulation process employing various binding agents (e.g., biopolymers, synthetic polymers, and inorganic materials) affords composite functional particles with modified morphological and surface properties that support easy isolation from the aqueous phase upon adsorption of Li ions. Biomaterials (e.g., chitosan, cellulose, alginate, and agar) are of particular interest because their structural diversity renders them amenable to coordination interactions with metal-based LISs to form three-dimensional bio-composite materials. The current review highlights recent progress in the use of biopolymer binding agents for the granulation of metal-based LISs, along with various crosslinking strategies employed to improve the mechanical stability of the granules. The study reviews the effects of granulation and crosslinking on adsorption capacity, selectivity, isolation, recovery, cycling performance, and the stability of the LISs. Adsorbent granulation using biopolymer binders has been reported to modify the uptake properties of the resulting composite materials to varying degrees in accordance with the surface and textural properties of the binding agent. The review further highlights the importance of granulation and crosslinking for improving the extraction process of Li ions from aqueous media. This review contributes to manifold areas related to industrial application of LISs, as follows: (1) to highlight recent progress in the granulation and crosslinking of metal-based adsorbents for Li ions recovery, (2) to highlight the advantages, challenges, and knowledge gaps of using biopolymer-based binders for granulation of LISs, and finally, (3) to catalyze further research interest into the use of biopolymer binders and various crosslinking strategies to engineer functional composite materials for application in Li extraction industry. Properly engineered extractants for Li ions are expected to offer various cost benefits in terms of capital expenditure, percent Li recovery, and reduced environmental footprint.
摘要：
对锂（Li）的高需求与清洁有关，可再生存储设备和电动汽车(EV)的出现。从水性介质中提取锂离子需要具有各种特性的高效吸附材料，如良好的吸附能力，良好的选择性，易于分离负载锂的吸附剂，和吸附的锂离子的良好回收。用于锂离子提取的金属基吸附剂材料的广泛使用与各种因素有关：（i）易于通过廉价和简便的模板技术制备，(ii)对基体中的锂离子具有优异的选择性，(iii)吸附离子的回收率高，和(iv)吸附剂的良好循环性能。然而,由于与从水性介质中分离负载的吸附剂材料相关的挑战,纳米尺寸的基于金属的锂离子筛(LIS)的使用受到限制。吸附剂造粒过程采用各种粘合剂(例如，生物聚合物，合成聚合物，和无机材料）提供了具有改性形态和表面性能的复合功能颗粒，这些颗粒在吸附锂离子时易于从水相中分离。生物材料(例如，壳聚糖,纤维素,海藻酸盐,和琼脂）特别令人感兴趣，因为它们的结构多样性使它们易于与金属基LIS配位相互作用以形成三维生物复合材料。当前的评论强调了使用生物聚合物结合剂进行金属基LIS造粒的最新进展，以及用于改善颗粒的机械稳定性的各种交联策略。研究综述了造粒和交联对吸附能力的影响。选择性,隔离,recovery,循环性能,以及LIS的稳定性。已经报道了使用生物聚合物粘合剂的吸附剂造粒根据粘合剂的表面和纹理性质将所得复合材料的吸收性质改性到不同程度。该综述进一步强调了造粒和交联对于改善从水性介质中提取锂离子的过程的重要性。这篇综述有助于与LIS的工业应用相关的多个领域，如下：（1）重点介绍了用于锂离子回收的金属基吸附剂的造粒和交联的最新进展，（2）突出优势，挑战,以及使用基于生物聚合物的粘合剂进行LIS造粒的知识空白，最后，（3）催化进一步的研究兴趣，使用生物聚合物粘合剂和各种交联策略来设计功能复合材料，以应用于Li提取工业。经适当设计的锂离子萃取剂有望在资本支出方面提供各种成本效益，%Li回收率，减少环境足迹。
