Galleguillos Madrid Felipe M, Salazar-Avalos Sebastián, Bergendahl Markus, Quispe Javier, Toro Norman, Casanueva-Yáñez Galvarino, Soliz Alvaro
Centro de Desarrollo Energético Antofagasta, Universidad de Antofagasta, Antofagasta, Chile.
Departamento de Ingeniería Química y Medio Ambiente, Universidad Católica del Norte, Antofagasta, Chile.
Front Chem. 2025 Aug 19;13:1659479. doi: 10.3389/fchem.2025.1659479. eCollection 2025.
The growing global demand for clean and sustainable energy has intensified the development of novel technologies capable of harnessing naturally available resources. Among these, blue energy, referring to the power generated from the mixing of waters with different salinities, has emerged as a promising yet underutilized source. This perspective presents a comprehensive synthesis of recent advances in electrochemical harvesting systems, with a particular focus on Mixing Entropy Batteries (MEBs) as efficient, membrane-free devices for salinity gradient energy recovery. Unlike conventional approaches such as Reverse Electrodialysis (RED) and Pressure Retarded Osmosis (PRO), which depend heavily on ion-exchange membranes and complex infrastructure, MEBs offer simplified and scalable architecture suitable for harsh environments and industrial effluents. The use of LiCl-based electrolytes enables significant blue energy recovery, achieving energy densities of 38.2 mJ/cm and power densities of 13.8 μW/cm, with excellent cycling stability. This system leverages the high solubility of LiCl (832 g/L) to create steep salinity gradients, utilizing LiFePO/FePO as the cathode and Ag/AgCl as the anode, with no observable performance degradation over 100 cycles. This work analyzes alternative electrode materials, including Prussian Blue analogues (copper hexacyanoferrate CuHCF), MnO, BiOCl, and polypyrrole, and explores their integration with unconventional water sources such as industrial brines, hypersaline reject streams, and treated wastewater, particularly within the resource-constrained context of the Atacama Desert. This manuscript consolidates experimental data, device designs, and comparative performance metrics, providing a critical framework for advancing blue energy technologies. It also underscores their potential role in circular economy models and off-grid renewable energy systems solutions.
全球对清洁和可持续能源的需求不断增长，这加剧了能够利用自然可用资源的新技术的开发。其中，蓝色能源是指由不同盐度的水混合产生的能量，已成为一种有前景但未得到充分利用的能源。本文全面综述了电化学采集系统的最新进展，特别关注混合熵电池（MEB），它是一种高效、无膜的盐度梯度能量回收装置。与传统方法如反向电渗析（RED）和压力延迟渗透（PRO）严重依赖离子交换膜和复杂基础设施不同，MEB提供了适用于恶劣环境和工业废水的简化且可扩展的架构。使用基于LiCl的电解质能够实现显著的蓝色能量回收，能量密度达到38.2 mJ/cm，功率密度达到13.8 μW/cm，具有出色的循环稳定性。该系统利用LiCl的高溶解度（832 g/L）来创建陡峭的盐度梯度，以LiFePO/FePO作为阴极，Ag/AgCl作为阳极，在100次循环中未观察到性能下降。这项工作分析了替代电极材料，包括普鲁士蓝类似物（六氰合铁酸铜CuHCF）、MnO、BiOCl和聚吡咯，并探索了它们与非常规水源如工业盐水、高盐度排放流和处理后的废水的整合，特别是在阿塔卡马沙漠资源受限的背景下。本文整合了实验数据、器件设计和比较性能指标，为推进蓝色能源技术提供了关键框架。它还强调了它们在循环经济模式和离网可再生能源系统解决方案中的潜在作用。
