Advances in zinc-ion structural batteries

Electrical energy storage technologies have become a critical aspect of the whole clean energy system, which is fundamentally based on batteries. In the past decades, innovations in batteries changed the appearance of our lifestyle with portable devices. More recently, electrical vehicles have led the mind toward a promising clean world without fossil fuels. However, minimizing the weight and/or volume of such batteries is the critical design driver, and in the last decade, the idea of moving electric energy accumulation inside structural parts has been proposed and named structural batteries (SBs), in which structural elements should also act as electric energy accumulators. The work on structural batteries to date has mostly involved Li-ion batteries due to their acceptable performance. However, the adoption of Li-ion batteries must face the limited availability of lithium on the earth and safety during their manufacturing and use. These issues encouraged researchers to seek alternative battery systems that do not present their drawbacks. Zn-ion structural batteries are a promising alternative to lithium-ion batteries in the post-lithium era. Zinc is one of the most abundant elements on the planet and can be found at low prices. Zinc-based batteries also have the potential to use lower-cost production procedures because they do not require particular dry room conditions, which means the ability to operate in the air, allowing for large-scale assembly. Although Zn-ion batteries have numerous advantages, the development of Zn-ion structural batteries is still in its early stages (low Technology Readiness Level, TRL), and additional study is required. This review seeks to provide a concise description of current breakthroughs in materials and architecture design, as well as a critical assessment of the performance and limitations of the solutions adopted for zinc-based structural batteries. The difficulties in constructing Zn-ion structural batteries are discussed. This is the first complete examination of these batteries, and it provides an overview of the technology with the aim of promoting future structure battery chemistry research.