High-Voltage, Long Term-Stable and Wearable Zinc-Ion Hybrid Batteries with Gel Biopolymer Electrolytes
Authors: Kasprzak Dawid , Tao Li , Wu Zhenrui , Xu Jia , Zhang Yue , Liu Jian 
Published: August 2024

We are on the eve of the energy transition towards the phase-out of coal, electromobility and renewable power supply. Lithium-ion batteries (LIBs) and electric double-layer capacitors (EDLCs) are complementary energy storage devices supporting this technological change. They have dominated the commercial market of power sources, serving as energy supplies for various technologies ranging from daily electronics and gadgets through electric vehicles to management systems of the intermittent electric grid. However, conventional energy storage systems present some challenges regarding operational safety, the expected increase in production costs, the risk of limited availability of raw natural resources, and universal waste disposal.1,2

Zinc-ion rechargeable power sources, including batteries and hybrid supercapacitors, are a promising alternative to commercial LIBs and EDLCs.3,4 This technology integrates attractive features, such as high gravimetric and volumetric theoretical capacity, low cost, high safety, and environmental friendliness. Nevertheless, the widespread adoption of zinc-ion systems for powering commercial devices still faces challenges related to electrode design, the risk of liquid electrolyte leakage, rigid construction, and the presence of synthetic polymer-based components. This research attempts to address the aforementioned shortcomings by exploring the concept of biopolymer-based zinc-ion systems.
Herein, we present zinc-ion hybrid batteries employing gel biopolymer electrolytes. Batteries and dual-ion hybrid batteries of aqueous Zn-ion technology operate according to similar mechanisms, differing on the catholyte side. In Zn-ion batteries, zinc ions are involved in the reactions on both electrodes, whereas hybrid systems have cathodes adopted from alkaline metal-ion technologies, operating according to intercalation/deintercalation processes of monovalent cations, e.g., Li-ion, Na-ion, K-ion, etc.5 As observed, hybrid devices are feasible with fast kinetics, good stability, and flat and high discharge voltage plateau. The application of gel electrolytes additionally improves their performance on the anode side, facilitating Zn stripping/plating processes due to homogeneous current distribution and flat Zn deposition. Generally, the presented idea emerges as a promising strategy, offering an efficient, safe, low-cost, non-combustive, flexible and sustainable technology. Particular attention is paid to overcoming LIB performance and environmental limitations whilst developing wearable features through innovative biobased technological improvements.
References
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(2) Simon, P.; Gogotsi, Y.; Dunn, B. Where Do Batteries End and Supercapacitors Begin? Science (80-. ).
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(3) Wang, Y.; Sun, S.; Wu, X.; Liang, H.; Zhang, W. Status and Opportunities of Zinc Ion Hybrid Capacitors: Focus on Carbon Materials, Current Collectors, and Separators. Nano-Micro Lett.
2023, 15 (1), 78.
(4) Tang, B.; Shan, L.; Liang, S.; Zhou, J. Issues and Opportunities Facing Aqueous Zinc-Ion Batteries. Energy Environ. Sci.
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(5) Shi, Y.; Chen, Y.; Shi, L.; Wang, K.; Wang, B.; Li, L.; Ma, Y.; Li, Y.; Sun, Z.; Ali, W.; Ding, S. An Overview and Future Perspectives of Rechargeable Zinc Batteries. Small
2020, 16 (23), 2000730.

Figure 1. Work concept.

Figure 1