PAM-based hydrogel electrolyte for hybrid rechargeable aqueous (Zn and Li-ion) battery (2023)

Materials Today: Proceedings, Volume 49, Part 6, 2022, pp. 2495-2500

In the present work, the effect of indium (In) doping on the various properties of the zinc oxide (ZnO) thin films was investigated. The pure and 5% In doped ZnO thin films have been synthesized via the successive ionic layer adsorption and reaction (SILAR) method on glass substrates. The X-Ray Diffraction (XRD) analysis clearly indicated the well-crystalline wurtzite structure of ZnO and 5% In-ZnO films. The Scanning Electron Microscopy (SEM) study depicted the formation of granular and nanoflower structures on the surface of the synthesized films. The band-gap energy and the grain size values of 5% In-ZnO were found to be 3.32 eV and 22.33 nm, respectively. Also, the indium incorporation into ZnO made a significant change on the structural, morphological properties, and enhanced the gas-sensing performance of ZnO host material.

Materials Today: Proceedings, Volume 49, Part 6, 2022, pp. 2459-2463

The concept of back-contact device architecture for perovskite solar cells (PSCs) is a promising alternative to PSCs with the traditional sandwich-type device architecture. The most convenient and low cost method to fabricate back-contact electrodes for PSCs is using microsphere lithography as it can be performed without expensive photolithography tools and cleanroom environment. Deposition of a monolayer of polystyrene microbeads on the surface of cathode substrates (conductive transparent oxide glass substrates covered with a thin layer of SnO₂) is achieved through a self-assembly process. The self-assembly process is based on electrostatic attraction forces between negatively charged microbeads and the positively charged cathode surface. The self-assembled monolayer of polystyrene microbeads is used as a sacrificial polymer mask to fabricate the anode layer on top of cathodes. The back-contact electrodes are obtained after removing the sacrificial polymer mask through a lift-off process.

Energy Storage Materials, Volume 47, 2022, pp. 187-194

Pollution of the discarded batteries to the environment has become a challenge that needs to be solved urgently. The innovation of energy storage devices with degradable materials are essential to this mission. Here, an environmentally friendly PVA-gelatin hydrogel-based water-in-salt electrolytes (HiSE) was developed for the high-performance Zn dual-ion battery (ZDIB) with transient degradation advantage. Specifically, PVA and gelatin collectively constrain the water coordinated with ZnCl₂ inside the polymer network, which enhances battery reaction dynamics due to the reduced radius of Zn hydrate ion. Several advantages are combined into a single platform in this battery, including not only fast degradation in water, high ionic conductivity, dendrite suppression and high operating voltage, but also easy replication and expansion. The HiSE-based ZDIB exhibits operating voltage of 2.0V, excellent rate performance and good stability with a capacity retention of 96.2% after 8000 cycles. Our work paves a way towards sustainable and high-performance energy storage systems.

Chemical Engineering Journal, Volume 433, Part 2, 2022, Article 133532

Naturally derived hydrogels have emerged as advanced manufacturing materials due to their biosafety, biocompatibility, and eco-friendly property while retaining large amounts of water. Here, we demonstrate that biopolymeric hydrogel interphase derived from abundant natural polysaccharide exhibits successful stabilization of 3D structured Zn anodes for dendrite-free aqueous zinc-ion batteries (ZIBs). The cross-linked natural hydrogel interphase on Zn anodes guides the uniform stripping/plating of Zn²⁺ for dendrite-free homogeneous Zn deposition and effectively avoids direct contact between reactive aqueous electrolytes and Zn anodes, inhibiting the parasitic side such as the hydrogen evolution reaction. Furthermore, the thin hydrogel interphase enables employing liquid electrolytes without lowering volumetric energy density. Such characteristic allows high ionic conductivity and, more importantly, significantly reduces cell resistance compared to previous ZIBs with only hydrogel electrolytes. These features afford highly stable zinc plating/stripping behaviors at high areal current density (10mAcm⁻²) and capacity (2 mAh cm⁻²) for 1500h, enabling durable cycle stability of full cells paring with MnO₂ cathodes during 3000 cycles at 2 Ag⁻¹ without capacity fading. Our strategy not only suggests a “green” method for developing dendrite-free aqueous ZIBs but also provides natural polymers with expansion into future aqueous energy storage fields.

Materials Letters, Volume 306, 2022, Article 130954

Aqueous Zn-ion battery has developed as an alternative to overcome the limitations of conventional Li-ion batteries, but its application is insufficient due to low reversibility and electrochemical reliability. In this study, we developed a cathode for aqueous Zn-ion battery with improvement of reversibility and electrochemical reliability utilizing phthalocyanine (PTC) that efficiently transports metal ions and electrons. The intercalation/de-intercalation reaction of Zn²⁺ ions changes according to the central metal ligand ion of PTC, and iron (II) coordinated PTC exhibited the outstanding energy storage capacity (161.34 mAh/g) and electrochemical reliability (99%, 100 cycles). Based on maximized electrochemical performance and reliability, Zn-ion flexible battery was successfully demonstrated by utilizing air-spray coating.

Energy Storage Materials, Volume 48, 2022, pp. 244-262

With steadily growing environmental problems by synthetic compounds, using eco-friendly biomass-derived biopolymers and other native materials has drawn tremendous attention and extensive interest, to replace traditional petroleum-based materials. Biopolymer-based hydrogels, as emerging and renewable electrolyte materials, have been considered to be competitive candidates for flexible and smart electrochemical energy storage and conversion devices due to the low cost, eco-friendly and degradability. Recently, biopolymer-based hydrogel electrolytes with desirable structure design or functional development have exhibited broad application prospects in diverse energy storage and conversion devices, such as multifunctional supercapacitors, flexible lithium-ion batteries and zinc-ion batteries. Herein, the characterization, synthesis, and performance validation of biopolymer-based hydrogel electrolytes are summarized, analyzed, and discussed. Current progress of electrochemical performance and additional functions (such as self-healing, stretchability, anti-freezing, and etc.) in developing biopolymer-based hydrogel electrolytes for supercapacitors and batteries are comprehensively reviewed. We also present the remaining challenges of using biopolymer-based hydrogel electrolytes for advanced energy storage and conversion devices and propose the underlying approaches to facilitate further development and research.