Study on a newly proposed ZnO-LiFePO4 piezoelectric composite-based lithium-ion sieve for extracting lithium from saline lake brine under natural conditions

Lithium is a crucial strategic resource that plays a pivotal and instrumental role in facilitating the advancement of new energy technologies. The rapid growth of the renewable energy industry has resulted in a critical shortage of lithium salt supplies. The extraction of lithium from saline lake brine is characterized by its low energy consumption and cost-effectiveness, making it a prominent area of research in the field. However, the development and widespread application of lithium extraction technology under natural settings have tremendous relevance for lithium extraction in this region because of the severe natural environment and limited industrial base in the majority of saline lake areas. In this paper, zinc oxide with piezoelectric properties was prepared using hydrothermal method, and it was combined with lithium iron phosphate through sintering method to create a piezoelectric adsorbent capable of responding to mechanical energy. The adsorbent can capture wave energy in the saline lake and generate polarized electrons to accelerate theredox process, resulting in selective lithium ion adsorption. After 48 h of reaction with a 20 % zinc oxide loading and a sintering temperature of 200℃, the capacity of the piezoelectric adsorbents for lithium increased to 35.27 mg/g, as shown by experimental results. This study proposes a novel method for extracting lithium directly from saline lake brines under natural conditions, as well as a new application of piezoelectric materials.