SEPARATION AND PURIFICATION TECHNOLOGY
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2020
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IF 5.774
Zheng Zhang,Xiao Du,Qiang Wang,Fengfeng Gao,Tongtong Jin,Xiaogang Hao,Pengfei Ma,Jun Li,Guoqing Guan
A scalable three-dimensional (3D) porous composite electroactive film consisting of λ-MnO 2 , reduced graphene oxide (rGO) and calcium alginate (Ca-alg) was successfully fabricated and employed for the selective extraction of Li + ions with low concentration via an electrochemically switched ion exchange (ESIX) technology. The Li + ion adsorption capacity of the obtained λ-MnO 2 /rGO/Ca-alg composite electroactive film reached as high as 32.7 mg g −1 and more than 90% of its equilibrium adsorption capacity was achieved in 1 h. The λ-MnO 2 /rGO/Ca-alg composite electroactive film displayed evident selectivity towards Li + ions. The separation factors for Li + /Na + and Li + /Mg 2+ reached 1040.57 and 358.96, respectively, while tested in simulated brine. The composite film also showed superior electrochemical stability, and the normalized ion exchange capacity retained at 98.3% of its initial value even after 100 successive cycles. The excellent Li + ion recovery performance of the obtained composite film should be attributed to its low ion transfer resistance owing to the porous network structure and the potential-responsive ion-pumping effect in the ESIX process. In addition, a large-scale of such a composite electroactive film could be effectively fabricated by controlling the spreading area of the mixed solution consisting of λ-MnO 2 , rGO and alginate binder. It is expected that such a scalable 3D porous composite film could be a promising alternative for the recovery of lithium ions from salt lake brine.
研究领域:
材料科学
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环境科学
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电化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2025
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IF 4.1
Hu Fu,Weigang Zhu,Wenhua Xu,Zhongwei Zhao
Lithium-ion detection is necessary for extraction of lithium. Electrochemical sensors based on spinel LiMn 2 O 4 /λ-MnO 2 are expected to enable low-cost detection of lithium ions. Many studies demonstrate preferential intercalation of lithium ions, but little research has been done on how the differences in intercalation between lithium and other ions arise. Here, the differences in intercalation were identified by electrochemical impedance spectroscopy. Lithium ions were preferentially intercalated into λ-MnO 2 because of low charge transfer impedance. The apparent diffusion coefficient of sodium or potassium ions was one order of magnitude lower than that of lithium ions, while that of magnesium or calcium ions was two orders of magnitude lower. Therefore, insignificant intercalation of sodium, magnesium, potassium, and calcium ions slowed down diffusion of lithium ions through the channel and obstructed lithium-ion intercalation. The concentration of lithium ions was detected in brine of Baqiancuo Salt Lake by stripping voltammetry using λ-MnO 2 and an average recovery of 95.0 % was achieved. This study gives insights into ion intercalation of LiMn 2 O 4 in brine, which favors improvement of lithium-ion sensor based on LiMn 2 O 4 . In addition, the investigation facilitates understanding of the selectivity of similar materials (e.g., LiFePO 4 and Prussian blue analogous) in intercalation process.
研究领域:
材料科学
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电化学传感器
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2026
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IF 13.2
Zirui Wang,Xiao Du,Xuefeng Zhang,Guoliang Nie,Zhong Liu,Xiaowei An,Xuli Ma,Shanxia Luo,Xiaogang Hao
Electrically Switched Ion Exchange (ESIX) technology boasts advantages of high selectivity, low energy consumption, and environmental friendliness, and its core material, LiMn 2 O 4 , can efficiently separate lithium through unique lattice sieving and charge matching effect, yet it suffers from severe performance degradation in brine environments with ultra-high Mg/Li ratio. Currently, the microscopic mechanism responsible for this degradation remains unclear. In this study, we propose a “confined-capture-induced blocking” mechanism using experimental investigations, characterization techniques, and density functional theory (DFT) calculations. Specifically, the strong Coulomb interaction between high-charge-density Mg 2+ and the O atoms at the entrances of the [111] channels (the Li + migration channels) of LiMn 2 O 4 results in blockage of the channel entrances, thereby blocking the intercalation of Li + . Based on this mechanism, we propose a targeted solution: adopting a dynamic adsorption mode with solution flow. This approach effectively mitigates the adverse effects of Li + concentration polarization and Mg 2+ enrichment near the electrode, which lead to an abnormally high Mg/Li ratio in static adsorption, thereby enhancing the adsorption capacity from 1.437 mg/g in static adsorption to 5.124 mg/g at a flow rate of 2 l/min. Subsequently, pilot-scale experiments further validate the effectiveness of this strategy. This research provides theoretical support, engineering evidence, and practical guidance for the development of lithium extraction technology from salt lakes with ultra-high Mg/Li ratio.
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Zhixiang Meng,Meiling Wang,Xun Cao,Tian Wang,Yongchao Wang,Yike Xu,Weifeng Liu,Lin Chen,Yizhong Huang,Xuguang Liu
Li + ion-sieve (LIS) films, foams, or granules have been fabricated to immobilize LIS to overcome powder loss for Li extraction from seawater. However, the practical application is still restricted by their low swelling ability and poor flexibility to withstand harsh marine environment for a long time. Here, a highly elastic interconnected porous LIS nanocomposite hydrogel with tunable pore structure and flexibility, as well as good swelling property, is prepared by using LIS (viz. λ-MnO 2 ) as a pore self-modifier during the in-situ fabrication of polypyrrole (PPy) and polyvinyl alcohol (PVA) interpenetrating hydrogel (denoted as λ-MnO 2 @IG). In addition to physical confinement interactions, the strong coordination/chelation and electrostatic interactions between λ-MnO 2 nanoparticles and polymer chains enable well-dispersed λ-MnO 2 nanoparticles to be confined in a rich network structure. Even at a marine environment (pH 8.3), the λ-MnO 2 @IG hydrogel exhibits superior Li + adsorption performance (20.6 mg g −1 HMO), outperforming most adsorbents containing LIS. Specially, the porous hydrogel is easily recyclable and exhibits super-stable cyclic Li extraction performance, which are directly attributable to the further-improved pore structure in continuous regeneration process. This study provides a self-regulating strategy to design LIS porous hydrogels with controllable porosity, high flexibility, good swelling ability, and excellent cycle stability to address the growing Li + demanding challenges.
研究领域:
材料科学
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环境工程
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化学工程
✓ 已验证
DOI
高影响因子
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