Coulometric ion sensing with Li+-selective LiMn2O4 electrodes
Coulometric ion sensing with Li+-selective LiMn2O4 electrodes
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DOI：
10.1016/j.elecom.2022.107302
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发表时间：
2022-05
影响因子：
5.4
通讯作者：
Yan Lyu;T. Han;Lijie Zhong;Yitian Tang;Longbin Xu;Yingming Ma;Y. Bao;Shiyu Gan;J. Bobacka;Li Niu
中科院分区：
文献类型：
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作者：
Yan Lyu;T. Han;Lijie Zhong;Yitian Tang;Longbin Xu;Yingming Ma;Y. Bao;Shiyu Gan;J. Bobacka;Li Niu
本工作以LiMn2O4(LMO)为离子识别和信号传导层，研究了一种用于固体接触离子选择电极的库仑信号读出方法。LMO的氧化还原过程与Li+离子的可逆插层/排出有关，允许对水溶液中的Li+离子进行库仑传感。随着LMO活性面积(质量负载量)的增加，对于给定的Li+离子活度变化，库仑信号增加。LMO良好的氧化还原可逆性和相对较低的电阻有助于实现高信号放大和相对快速的响应。研究发现，用传统的锂离子选择性增塑聚氯乙烯膜覆盖LMO层可以显著降低库仑响应。因此，LMO作为锂离子选择性电极材料和离子-电子换能器的组合应用被发现与库仑信号读出方法高度兼容，特别是在检测高Li+浓度下的微小Li+活度变化时。
A coulometric signal readout method, which was originally developed for solid-contact ion-selective electrodes, was investigated in this work using LiMn2O4(LMO) as a combined ion-recognition and signal-transduction layer. The redox process of LMO, which is associated with reversible intercalation/expulsion of Li+ions, allowed coulometric sensing of Li+ions in aqueous solutions. On increasing the active area (mass loading) of LMO, the coulometric signal increased for a given change in Li+ion activity. The excellent redox reversibility of LMO and its relatively low resistance were instrumental in achieving a high signal amplification together with a relatively fast response. Coating the LMO layer with a conventional Li+-selective plasticized PVC membrane was found to dramatically lower the coulometric response. Hence, the application of LMO as a combined Li+-selective electrode material and ion-to-electron transducer was found to be highly compatible with the coulometric signal readout method, especially for detecting small Li+activity changes at high Li+concentrations.