SPS/LMO/CNT膜的构筑及其电驱动锂离子的分离性能研究OA

The efficient selective separation of lithium ions(Li+)from high-magnesium-lithium ratio salt lake brine is a key issue that urgently needs to be addressed in the development of the salt lake lithium extraction industry in China.Electrochemically switched ion permselectivity(ESIP)technology,by integrating ion selective recognition and continuous permeation transport mechanisms,provides an effective approach for the efficient,continuous and selective separation of Li+.To address the inherent insufficient conductivity and poor film-forming performance of lithium manganese oxide(LMO),a SPS/LMO/CNT ternary composite membrane electrode was designed and prepared using sulfonated polystyrene(SPS)as the binding matrix,carbon nanotubes(CNT)as the conductive framework,and LMO as the Li+selective recognition unit.The membrane electrode was applied in an ESIP system to systematically investigate its electrochemical response mechanism and Li+separation performance.The results demonstrate that the SPS/LMO/CNT membrane not only exhibits a synergistic response behavior of electric double-layer capacitance and pseudocapacitance,but also enables reversible deintercalation and intercalation of Li+.Under the optimal LMO loading amount(400 mg),the Li+removal rate of the SPS/LMO/CNT membrane reaches 67.86%.In the coexisting system of Li+and magnesium ions,the Li+selectivity of the SPS/LMO/CNT membrane is higher than 20,demonstrating excellent Li+selective recognition and migration capabilities.Meanwhile,the dense cross-linked network structure formed by the interactions among SPS,LMO and CNT endows the membrane with good cycling stability,enabling five consecutive Li+separation cycles.