Determination of lithium ions by stripping voltammetry using single-crystal LiFePO4

Hu Fu; Wenhua Xu; Zhongwei Zhao; Lihua He

doi:10.1016/j.talanta.2023.125499

Determination of lithium ions by stripping voltammetry using single-crystal LiFePO₄

Talanta. 2024 Mar 1:269:125499. doi: 10.1016/j.talanta.2023.125499. Epub 2023 Dec 5.

Authors

Hu Fu¹, Wenhua Xu², Zhongwei Zhao³, Lihua He⁴

Affiliations

¹ School of Metallurgy and Environment, Central South University, Changsha, Hunan, 410083, China.
² School of Materials Science and Engineering, Central South University, Changsha, Hunan, 410083, China.
³ School of Metallurgy and Environment, Central South University, Changsha, Hunan, 410083, China; Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals, Changsha, Hunan, 410083, China. Electronic address: zhaozw@csu.edu.cn.
⁴ School of Metallurgy and Environment, Central South University, Changsha, Hunan, 410083, China; Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals, Changsha, Hunan, 410083, China.

PMID: 38056414
DOI: 10.1016/j.talanta.2023.125499

Abstract

Determination of lithium ions is very important for extraction of lithium from salt lakes. Electrochemical sensor is an ideal choice, but it is not available so far. Here, a voltammetric sensor based on lithium iron phosphate (LiFePO₄) was developed. Single-crystal LiFePO₄ dominated by the (010) lattice plane was synthesized using hydrothermal method; it had good selectivity for lithium ions. Lithium ions were preferentially intercalated into LiFePO₄ even if molar ratio of sodium ions, potassium ions, magnesium ions or calcium ions to lithium ions reached 10:1. The intercalation and deintercalation of interfering ions should be avoided because this reduced the selectivity of LiFePO₄ for lithium ions. Lithium ion concentration of synthetic Uyuni Salt Lake solution was determined using the standard addition method. The measurement result was only 0.34 % higher than the theoretical value. The sensor provides a highly selective lithium ion analysis method at an extremely low cost, which was very promising to be widely used.

Keywords: Determination; Lithium ions; Lithium iron phosphate; Stripping voltammetry.