Ultra-low cost and high Coulombic efficiency aqueous zinc-ion battery

In a significant breakthrough for large-scale energy storage systems (EESs), a team of researchers has developed a high-performance, low-cost aqueous zinc-iron battery (AZIB) based on a novel deposition/dissolution mechanism. This innovation addresses key challenges in renewable energy storage, such as cost, safety, and cycling stability, offering a promising solution for grid-scale applications.

Traditional rechargeable batteries often rely on expensive or unstable cathode materials, such as vanadium or manganese-based compounds, which increase manufacturing costs and limit long-term viability. In contrast, the newly designed zinc-iron battery utilizes abundant and inexpensive materials—iron (Fe) and zinc (Zn)—to achieve remarkable electrochemical performance. The system employs a unique deposition/dissolution mechanism, where active ions are sourced directly from the electrolyte rather than embedded in the electrode, significantly reducing production expenses and enhancing energy density.

The key to this advancement lies in the optimized electrolyte formulation: a mixture of 1 M ZnSO₄ +1 M FeSO₄ with 0.01 M H₂SO₄ (ZFH). This combination stabilizes the Fe²⁺ ions and ensuring highly reversible deposition and dissolution reactions. In testing, the battery demonstrated near-100% Coulombic efficiency (CE) and maintained a stable discharge voltage of 0.34 V (vs. Ag/AgCl) over extended cycles. When configured as a full cell with a graphite felt (GF) cathode and zinc metal anode, the system delivered outstanding cycling stability, retaining high efficiency over 2,300 cycles at a current density of 5 mA cm⁻².

Further analysis revealed that the cathode reaction involves the transformation between Fe²⁺ and FeOOH·0.5H₂O. The process confirmed through techniques such as Fourier transform infrared spectroscopy (FTIR), electrochemical quartz crystal microbalance (EQCM), and X-ray photoelectron spectroscopy (XPS). The findings provide critical insights into the reaction mechanism, paving the way for further optimization of similar battery systems.

This research represents a major step forward in developing cost-effective and sustainable energy storage technologies. By leveraging Earth-abundant materials and a simple yet efficient design, the zinc-iron battery could play a vital role in integrating renewable energy sources like wind and solar into the power grid. The team’s work highlights the potential of deposition/dissolution-type cathodes to revolutionize EESs, offering a scalable and economically viable alternative to conventional battery technologies.

With further development, this innovation could accelerate the global transition to clean energy, providing reliable storage solutions that are both affordable and environmentally friendly. The study has been published in a leading scientific journal, drawing attention from industry experts and policymakers alike.

About Nano Research

Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.