锂，作为新世纪的储能元素，重要性与需求量与日俱增。地球上仅有36%的锂资源存在于矿石中，多于60%的锂以液态的形式存储于盐湖与海水中。中国的盐湖普遍高镁低锂，镁锂浓度比一般大于60倍，传统的煅烧法、沉淀法、萃取法、膜分离法等很难高效且低成本地分离镁和锂。锂离子筛吸附法可以从卤水中选择性地吸附锂离子，分离效率高，是极具前景的提取液态锂的方法。然而，研究最广泛的锰系锂离子筛会出现Mn3+的歧化以及Jahn-Teller效应，导致溶损率高、吸附循环性差、稳定性差等问题。钛系锂离子筛具有更强的结构稳定性与低溶损率，利于循环使用。但传统的钛系锂离子筛易团聚、比表面积小，大大降低了吸附速率；部分钛系锂离子筛的储锂位点并不能完全利用，导致其实际容量远低于理论预期。同时，锂离子筛在二次成型时需要添加支撑材料与粘结剂，这也增加了锂离子的迁移路径，降低了总体的吸附比容量。本文以简单的一步水热反应后热处理的方法制备了自支撑的Li4Ti5O12一维纳米线前驱体，随后通过酸浸的方式获得H4Ti5O12锂离子筛。此钛系锂离子筛拥有较多的储锂位点、稳定的尖晶石结构与较高的比表面积，不需要二次成型。因此，表现出优异的锂吸附性能。在初始锂离子浓度为1000 mg·L-1，pH=9与11的溶液中分别具有21.3 mg·g-1与30.2 mg·g-1的提锂容量。在镁锂比为11的模拟盐湖水中，Li+的选择性系数α均达到400以上。在九次循环后仍然保持20 mg·g-1的锂吸附容量，单次Ti4+溶损仅0.7%，高于锰系材料单次2%至4%的溶损率。本文利用Langmuir模型、Freundlich模型、D-R模型、热力学模型、伪一级和伪二级动力学模型与颗粒扩散模型分别对锂离子筛吸附曲线进行分析，提出两步非控速与两步控速过程的吸附离子交换机理。本文利用自降解模板法制备了直径合适的聚吡咯纳米管，对蒽醌-2-羧酸（ACQ）电极材料进行封装。聚吡咯纳米管具有大孔隙与薄管壁，可在提升材料整体导电性的同时对ACQ进行一维的物理化学协同限域，减少了有机材料ACQ的溶解。此外，聚吡咯在酸掺杂后具有容量，提升了复合有机电极的总容量密度。关键词：盐湖提锂；锂离子筛；吸附；溶损；有机电极材料

Lithium, as an energy storage element in the new century, is of increasing importance and demand. Only 36% of the earth's lithium resources exist in ores, and more than 60% of lithium is stored in salt lakes and seawater in liquid form. Salt lakes in China are generally high in magnesium and low in lithium. The concentration ratio of magnesium to lithium is generally greater than 60. Traditional calcination, precipitation, extraction and membrane separation methods are difficult to separate magnesium and lithium efficiently and at a low cost. Lithium ion sieve adsorption method can selectively adsorb lithium ions from brine with high separation efficiency, which is a promising method for extracting liquid lithium. However, the most widely studied manganese based lithium-ion sieve will inevitably appear the disproportionation of Mn3 + and Jahn-teller effect, resulting in high dissolution loss rate, poor adsorption cycle and poor stability. Titanium based lithium ion sieve has stronger structural stability and low dissolution loss rate, which is conducive to recycling. However, the traditional titanium based lithium ion sieve is easy to agglomerate and has small specific surface area, which greatly reduces the adsorption rate; The lithium storage sites of some Ti based lithium-ion sieves can not be fully utilized, resulting in the actual capacity much lower than the theoretical expectation. At the same time, support materials and binders need to be added in the secondary molding of lithium ion sieve, which also increases the migration path of lithium ion and reduces the overall adsorption capacity.In this paper, self-supporting Li4Ti5O12 nanowire precursors were prepared by a simple one-step hydrothermal reaction followed by heat treatment, and then H4Ti5O12 lithium ion sieves were obtained by acid leaching. The titanium based lithium ion sieve has many lithium storage sites, stable spinel structure and high specific surface area, and does not need secondary molding. Therefore, it shows excellent lithium adsorption performance. In the solution with initial lithium ion concentration of 1000 mg·L-1 and pH = 9 and 11, the lithium extraction capacities are 21.3 mg·g-1 and 30.2 mg·g-1, respectively. The selectivity coefficient of Li + in the simulated salt lake water with Mg/ Li ratio of 11 is above 400. The lithium adsorption capacity has 20 mg·g-1 remained after nine cycles, and the dissolution loss of Ti4+ was only 0.7% in a single cycle, which was higher than the dissolution loss rate of 2% to 4% of manganese based materials.In this paper, Langmuir model, Freundlich model, D-R model, thermodynamic model, pseudo first order and pseudo second order kinetic model and particle diffusion model are used to analyze the adsorption curve of lithium ion sieve respectively, and the adsorption ion exchange mechanism of two-step non controlled and two-step controlled process is proposed.In this paper, polypyrrole nanotubes with suitable diameter were prepared by self degradation template method to encapsulate anthraquinone-2-carboxylic acid (ACQ) electrode materials. Polypyrrole nanotubes have large pores and thin tube walls, which can enhance the overall conductivity of the material, and at the same time limit the ACQ by one-dimensional physicochemical synergy, thus reducing the dissolution of ACQ. In addition, polypyrrole has capacity after acid doping, which improves the total capacity density of the composite organic electrode.Keywords: Lithium extraction from salt lake; Lithium ion sieve; Adsorption; Dissolution loss; Organic electrode materials