Zinc-iodine Battery Research Articles

A highly conductive gel electrolyte with favorable ion transfer channels for long-lived zinc-iodine batteries.

Aqueous rechargeable zinc-iodine batteries (ARZIBs), as a powerful energy alternative, have inherent advantages, such as low cost, good safety and environmental friendliness. Unfortunately, uneven Zn deposition with dendrite growth and undesirable side reactions seriously compromises the safety and stability of ARZIBs. Herein, a novel strategy is demonstrated to fabricate highly conductive iota-carrageenan (IC) gel electrolyte. The unique double helix structure with good mechanical properties provides favorable Zn2+ channels guided by sulfate groups, which enables confinement effect and orderly guidance of Zn deposition. Additionally, the activity of water molecules confined in the gel electrolyte is reduced, thus inhibiting the corrosion reactions of the zinc electrode. As a result, the gel electrolyte with remarkable ionic conductivity (42.95 mS cm-1) showed a good cycling stability over 1000 h. Importantly, the Zn-I2 batteries with the IC-Zn gel electrolyte demonstrated remarkable reversibility with an impressive capacity retention (91.9%) over 5000 cycles and high average coulombic efficiency (99.86%). This work provides a reliable strategy to develop natural polymer gel electrolytes to regulate the Zn deposition for advanced rechargeable Zn-I2 batteries.

Polyiodide shuttle inhibition in ethylene glycol-added aqueous electrolytes for high energy and long-term cyclability of zinc–iodine batteries

High-density ordered porous graphene is used as the iodine host material and ethylene glycol is added to electrolyte to inhibit the polyiodide shuttle, so high volumetric energy and long cycling life are achieved for the Zn–I2 batteries.

Single atom catalysts for triiodide adsorption and fast conversion to boost the performance of aqueous zinc–iodine batteries

In this work, I− poisoning mechanism is proposed for SACs selection to suppress shuttle effect in Zn–I2 batteries. It is found that I− formation and desorption are crucial to maintain the catalytic and adsorption role of metallic element.

An ion exchange membrane-free, ultrastable zinc-iodine battery enabled by functionalized graphene electrodes

The aqueous rechargeable zinc-iodine battery is a promising system due to its high theoretical capacity, zinc and iodine abundance, and safety of the aqueous electrolyte. However, several challenges need to be addressed for zinc-iodine batteries to be competitive, including self-discharge, sluggish kinetics, low practical energy density, and dendrite formation on zinc anodes. Here, we realize a high-performing zinc-iodine battery with long-term stability through a novel design of electrodes and electrolytes. A three-dimensional functionalized graphene cathode facilitates the iodide redox reactions as well as immobilizes the dissolved polyiodides, suppressing the detrimental shuttling effect. Additionally, we introduce a composite anode made of zinc coated with reduced graphene oxide. This design greatly enhances the performance and stabilizes the anode during repeated zinc stripping/plating preventing dendrite formation. The electrolyte is formulated in a way that allows the use of an economical and efficient glass fiber separator instead of the commonly employed ion-exchange membranes which are expensive and have a relatively high Ohmic resistance. Our optimized zinc-iodine batteries exhibit high current efficiencies of nearly 100%, along with stable specific capacities of 257, 186, 150, 84 mAh g−1 at corresponding current densities of 1, 2, 5, 10 A g−1. Furthermore, a long-term capacity retention of 96.7% at 5 A g−1 over 2000 cycles is achieved, outperforming many similar aqueous batteries. This work also provides valuable guidance in designing electrodes for other aqueous metal-halide energy storage systems.

Recognition of the catalytic activities of graphitic N for zinc-iodine batteries

Rechargeable aqueous Zinc-iodine (Zn-I2) battery is attractive because of its high energy density, intrinsic safety and eco-friendly. However, the formation of highly soluble triiodide (I3−) intermediates due to the sluggish iodine redox kinetics greatly compromise its durability and practical energy density. Here, we report that the formation and crossover of the triiodide could be suppressed by catalyzing the iodine conversion with nitrogen doped porous carbons, which afford a robust zinc iodine battery with high energy density (320 Wh·kg−1) and ultra-long cycle life of 10,000 cycles. Our fundamental studies reveal the electrocatalytic activities are sensitive to the type of N heteroatoms, as confirmed by the decreased activation energy, Tafel slope and improved faradic current density of the iodine redox took place on the graphitic N enriched host. These merits are stemmed from the significant electron redistribution from graphitic N in carbon to iodine molecules after interaction, which not only thermodynamically strengthen the adsorption/redox conversion efficiency but also dynamically boost the triiodide/iodide conversion by lowering the dissociation energy barrier. In addition, the favorable nucleation/electrodeposition of solid iodine on graphitic N during cycling also benefits such direct one step conversion. This work provides the reference basis for the correlation of the catalytic activities and performance of Zn-I2 batteries.

A highly reversible dendrite-free Zn anode via spontaneous galvanic replacement reaction for advanced zinc-iodine batteries

Rechargeable aqueous zinc-iodine batteries have received extensive attention due to their inherent advantages such as low cost, flame retardancy and safety. To address the safety concern associated with Zn dendrites, tin functional layer is introduced to the Zn surface via a spontaneous galvanic replacement reaction. This provides rapid deposition kinetics, thereby achieving the uniform Zn plating/stripping with a low overpotential (13.9 mV) and good stability for over 900 h. Importantly, the coupling of the advanced Zn anode with iodine in Zn-I₂ battery exhibits a high specific capacity of 196.4 mAh·g⁻¹ with high capacity retention (90.7%). This work provides a reliable strategy to regulate the reversible redox of zinc for advanced rechargeable batteries.

Physicochemical Confinement Effect Enables High-Performing Zinc-Iodine Batteries.

Zinc-iodine batteries are promising energy storage devices with the unique features of aqueous electrolytes and safer zinc. However, their performances are still limited by the polyiodide shuttle and the unclear redox mechanism of iodine species. Herein, a single iron atom was embedded in porous carbon with the atomic bridging structure of metal-nitrogen-carbon to not only enhance the confinement effect but also invoke the electrocatalytic redox conversion of iodine, thereby enabling the large capacity and good cycling stability of the zinc-iodine battery. In addition to the physical trapping effect of porous carbon with good electronic conductivity, the in situ experimental characterization and theoretical calculation reveal that the metal-nitrogen-carbon bridging structure modulates the electronic properties of carbon and adjusts the intrinsic activity for the reversible conversion of iodine via the thermodynamically favorable pathway. This work demonstrates that the physicochemical confinement effect can be invoked by the rational anchoring of a single metal atom with nitrogen in a porous carbon matrix to enhance the electrocatalytic redox conversion of iodine, which is crucial to fabricating high-performing zinc-iodine batteries and beyond by applying the fundamental principles.

In-MOF-Derived Hierarchically Hollow Carbon Nanostraws for Advanced Zinc-Iodine Batteries.

Hollow carbon materials are regarded as crucial support materials in catalysis and electrochemical energy storage on account of their unique porous structure and electrical properties. Herein, an indium-based organic framework of InOF-1 can be thermally carbonized under inert argon to form indium particles through the redox reaction between nanosized indium oxide and carbon matrix. In particular, a type of porous hollow carbon nanostraw (HCNS) is in situ obtained by combining the fusion and removal of indium within the decarboxylation process. The as-synthesized HCNS, which possesses more charge active sites, short and quick electron, and ion transport pathways, has become an excellent carrier for electrochemically active species such as iodine with its unique internal cavity and interconnected porous structure on the tube wall. Furthermore, the assembled zinc-iodine batteries (ZIBs) provide a high capacity of 234.1mAhg-1 at 1Ag-1 , which ensures that the adsorption and dissolution of iodine species in the electrolyte reach a rapid equilibrium. The rate and cycle performance of the HCNS-based ZIBs are greatly improved, thereby exhibiting an excellent capacity retention rate. It shows a better electrochemical exchange capacity than typical unidirectional carbon nanotubes, making HCNS an ideal cathode material for a new generation of high-performance batteries.

Tetraethyl orthosilicate steam induced silicon-based anticorrosion film enables highly reversible zinc metal anodes for zinc-iodine batteries

Zinc (Zn) metal anodes are badly troubled by the challenges of notorious dendrites and corrosion reactions from H2O and I3− ions during stripping/plating processes, impeding the commercial application of Zn-iodine (I2) batteries. In this work, we report a novel strategy for the in-situ construction of uniform silicon-based anticorrosion films on Zn metal anodes (Zn@Ts) through the treatment of tetraethyl orthosilicate (TEOS) steam on Zn disks for different times. TEOS can be decomposed into three-dimensional (3D) porous inorganic frameworks (SiOxCy) filled with organic polymers (SiCxOyHz) on Zn metal at 180 °C in autoclave. On the one hand, silicon-based composite layers can protect Zn metal from direct contact with aqueous electrolyte and stabilize the electrode/electrolyte interface, which hinders the occurrence of hydrogen evolution as well as corrosion reactions. On the other hand, 3D macroporous structure not only provides strong mechanical framework but also guides Zn2+ flux to homogenize Zn2+ concentration and realize uniform Zn nucleation/deposition, which contributes to suppress the growth of Zn dendrites. Zn@Ts symmetric batteries exhibit better cycling life of 5000 h comparing with bare Zn at 2 mA cm−2 and 2 mA h cm−2. Zn–I2 full-cells can achieve 89 mA h g−1 and 93% capacity retention after 20000 cycles.

Constructing fast-ion-conductive disordered interphase for high-performance zinc-ion and zinc-iodine batteries

<h2>Summary</h2> The issues of Zn dendrite and severe Zn²⁺ transport destabilization in the electrode/electrolyte interface have been the main obstacles to the commercialization of aqueous Zn-based batteries. Here, a disordered zinc silicate (ZSO) artificial solid electrolyte interphase with high Zn²⁺ conductivity (9.29 mS·cm⁻¹) is proposed to address these dilemmas. The disordered ZSO interphase possesses sufficient tunnels for fast Zn²⁺ transport and highly reversible Zn plating/stripping, which can redistribute the Zn²⁺ flux and guide uniform Zn deposition to achieve a dendrite-free Zn metal anode. As a proof of concept in zinc-ion batteries, the Zn@ZSO//NH₄V₄O₁₀ battery delivers a capacity of 336.8 mAh·g⁻¹ at 0.2 A·g⁻¹, with a capacity retention of 90.1% at 5 A·g⁻¹ over 1,000 cycles. As for the Zn@ZSO//I₂ battery, by inhibiting I₃⁻ diffusion, 97.98% of capacity is retained after shelving for 60 h. This work provides enlightenment into interface designing and iodide diffusion suppression to accelerate the commercialization of high-performance zinc-based batteries.

High performance rechargeable aqueous zinc-iodine batteries via a double iodine species fixation strategy with mesoporous carbon and modified separator

With the increasing requirement for high capacity energy storage systems, a large amount of recent work has focused on the development of zinc-iodine batteries (ZIBs) on account of high energy density, fast redox kinetics, and excellent reversibility. Nevertheless, low electron conductivity, the shuttle effect, and highly soluble iodine species (I2, I−, and I3−) have impeded their widespread application. In this study, metal organic framework-5 (MOF-5)-derived mesoporous carbon (MPC) loaded iodine (MPC/I2) cathode and the single-sided ketjen black modified cotton fiber (KB@CF) separator are designed to solve the problems mentioned above. That is, the double fixation strategy using MPC and KB@CF separators for iodine species suppresses the shuttle effect. Therefore, the ZIBs constructed with the MPC/I2 cathode and the KB@CF separator can exhibit excellent electrochemical performance. At the current density of 0.1 A g−1, a high discharge specific capacity of 137 mAh g−1 is still available after 300 cycles. Meanwhile, it exhibits a low capacity decay rate at long cycling (0.030% per cycle over 2000 cycles).

In Situ Synthesis of Cathode Materials for Aqueous High-Rate and Durable Zn–I2 Batteries

Rechargeable aqueous zinc–iodine batteries are considered as one of strong contenders for next-generation energy storage systems by virtue of their low cost and high safety. However, the shuttle effect of highly soluble I3– in zinc–iodine batteries leads to a rapid decrease in capacity and Coulomb efficiency during cycling, which seriously hinders their further development and application. Here, we developed an in situ synthesis of an aqueous fast-charging and ultrastable Zn–I2 battery cathode materials composed of mesoporous carbon and I2. Compounding I2 with highly conductive carbon is an effective method to facilitate electron and ion transport and confine polyiodides/I– conversion reaction inside pores, thereby eliminating polyiodides shuttle effect, which greatly improves cycling stability of Zn–I2 batteries. The developed Zn–I2 battery provides a specific capacity of 90 mAh g–1 at 5 A g–1, excellent multiplicative performance, and retains a capacity retention of 80.6% over an ultralong period of 39 000 cycles at 10 A g–1, superior to previously reported Zn–I2 batteries. Furthermore, Zn–I2 pouch cell retained 89% capacity retention over 1000 cycles at 0.5 A g–1. This work undoubtedly sets a precedent for ultralong cycle life Zn–I2 battery cathode materials and provides an important solution and pathway for the assembly of I2-based materials suitable for high-performance aqueous energy technologies.

Confining iodine into a biomass-derived hierarchically porous carbon as cathode material for high performance zinc–iodine battery

The practical application of aqueous zinc-iodine (Zn-I2) battery is mainly hindered by the limited electrical conductivity, sluggish kinetics and severe shuttle effect. In this regard, herein, we designed a biomass-derived hierarchically porous carbon (marked as BCHP) as an iodine host material for high-performance Zn-I2 battery. The hierarchically porous structure of BCHP is favourable for iodine confinements, electrolyte permeation as well as electron/ion transfers. As a result, the I-BCHP electrode exhibits superior electrochemical performance. A high discharge capacity of 100 mAh g−1 is still retained for over 150 cycles at a current density of 100 mA g−1. Our study provides an economical and effective scheme for the significant improvement of Zn-I2 battery performance.

Interface Coordination Stabilizing Reversible Redox of Zinc for High-Performance Zinc-Iodine Batteries.

Aqueous Zn batteries (AZBs) have attracted extensive attention due to good safety, cost-effectiveness, and environmental benignity. However, the sluggish kinetics of divalent zinc ion and the growth of Zn dendrites severely deteriorate the cycling stability and specific capacity. The authors demonstrate modulation of the interfacial redox process of zinc via the dynamic coordination chemistry of phytic acid with zinc ions. The experimental results and theoretical calculation reveal that the in-situ formation of such inorganic-organic films as a dynamic solid-electrolyte interlayer is efficient to buffer the zinc ion transfer via the energy favorable coordinated hopping mechanism for the reversible zinc redox reactions. Especially, along the interfacial coating layer with porous channel structure is able to regulate the solvation structure of zinc ions along the dynamic coordination of the phytic acid skeleton, efficiently inhibiting the surface corrosion of zinc and dendrite growth. Therefore, the resultant Zn anode achieves low voltage hysteresis and long cycle life at rigorous charge and discharge circulation for fabricating highly robust rechargeable batteries. Such an advanced strategy for modulating ion transport demonstrates a highly promising approach to addressing the basic challenges for zinc-based rechargeable batteries, which can potentially be extended to other aqueous batteries.

Recent Advances of Aqueous Rechargeable Zinc-Iodine Batteries: Challenges, Solutions, and Prospects.

Aqueous rechargeable zinc-iodine batteries (ZIBs), including zinc-iodine redox flow batteries and static ZIBs, are promising candidates for future grid-scale electrochemical energy storage. They are safe with great theoretical capacity, high energy, and power density. Nevertheless, to make aqueous rechargeable ZIBs practically feasible, there are quite a few hurdles that need to be overcome, including self-discharge, sluggish kinetics, low energy density, and instability of Zn metal anodes. This article first reviews the electrochemistry in aqueous rechargeable ZIBs, including the flow and static battery configurations and their electrode reactions. Then the authors discuss the fundamental questions of ZIBs and highlight the key strategies and recent accomplishments in tackling the challenges. Last, they share their thoughts on the future research development in aqueous rechargeable ZIBs.

Performance comparison of electro-polymerized polypyrrole and polyaniline as cathodes for iodine redox reaction in zinc-iodine batteries

At present, Zinc-iodine (Zn//I) batteries have attracted much attention due to their high safety and capacity. However, how to suppress the shuttling of polyiodide ions generated during charging processes is still a tricky problem. Herein, polyaniline (PANI) and polypyrrole (PPy) are electro-polymerized on carbon felt (CF) by constant current and used as cathodes for zinc-iodine (Zn//I) batteries. Electrochemical tests of the PANI@CF and PPy@CF electrodes prove that the PANI@CF electrode has a higher capacity, a stronger ability to suppress shuttling of polyiodine ions, and more excellent cyclic stability than the PPy@CF electrode. According to the material characterizations, the differences of both electrodes in electrochemical performances are mainly caused by the microstructures of PANI and PPy in both electrodes. The PANI has a micro-nano porous structure while the PPy is very dense. The porous PANI not only has more channels for the infiltration of electrolyte, but also can provide more active adsorption sites to minimize the shuttling of polyiodide ions to anode, ensuring the excellent performances of the PANI@CF. However, dense PPy seriously hinders the electrolyte diffusion and triggers the formation of an insulating dense iodine film, bringing poor performances to the PPy@CF. Ultimately, the PANI@CF electrodes achieves the most specific capacity of 235.9 mAh g−1 at 0.35 A g−1 (∼1.7 C) and performs out long cycle life with high stability (75.7% capacitiy rention after 10,000 cycles) at 3.5 A g−1 (∼17 C) in Zn//I battery, manifesting the porous PANI@CF electrode is a greatly promising candidate as cathode for Zn//I batteries in actual application.

A Universal Polyiodide Regulation Using Quaternization Engineering toward High Value-Added and Ultra-Stable Zinc-Iodine Batteries.

The development of aqueous rechargeable zinc‐iodine (Zn‐I2) batteries is still plagued by the polyiodide shuttle issue, which frequently causes batteries to have inadequate cycle lifetimes. In this study, quaternization engineering based on the concept of “electric double layer” is developed on a commercial acrylic fiber skeleton ($1.55–1.7 kg−1) to precisely constrain the polyiodide and enhance the cycling durability of Zn‐I2 batteries. Consequently, a high‐rate (1 C–146.1 mAh g−1, 10 C–133.8 mAh g−1) as well as, ultra‐stable (2000 cycles at 20 C with 97.24% capacity retention) polymer‐based Zn‐I2 battery is reported. These traits are derived from the strong electrostatic interaction generated by quaternization engineering, which significantly eliminates the polyiodide shuttle issue and simultaneously realizes peculiar solution‐based iodine chemistry (I−/I3 −) in Zn‐I2 batteries. The quaternization strategy also presents high practicability, reliability, and extensibility in various complicated environments. In particular, cutting‐edge Zn‐I2 batteries based on the concept of derivative material (commercially available quaternized resin) demonstrate ≈100% capacity retention over 17 000 cycles at 20 C. This work provides a general and fresh insight into the design and development of large‐scale, low‐cost, and high‐performance zinc‐iodine batteries, as well as, other novel iodine storage systems.

Eutectic electrolyte based on N-methylacetamide for highly reversible zinc–iodine battery

A eutectic electrolyte strategy is proposed for zinc-iodine battery. Both the reasonable solvated structure and suppressed generation of I3− as an intermediate product achieve the high reversible I−/I0 conversion.

Elucidating the regulation mechanism of the photoelectrochemical effect of photocathodes on battery discharge voltages: a case study of aqueous zinc-iodine batteries.

We demonstrated a method to increase the discharge voltages of zinc-iodine batteries by introducing a p-type semiconductor photocathode to trigger the photoelectrochemical reduction reaction of the cathode redox. Accordingly, the photogenerated voltage across the semiconductor/liquid junction interface would be added to the discharge voltages of zinc-iodine batteries, realizing a discharge voltage (1.49 V) exceeding the theoretical value (1.30 V) under illumination, which is equivalent to an energy density increase of 31% compared to that of zinc-iodine batteries under dark conditions.

A renewable biomass-based lignin film as an effective protective layer to stabilize zinc metal anodes for high-performance zinc–iodine batteries

A renewable biomass-based lignin film on Zn anodes was constructed through the robust coordination interaction with Zn2+ and strong adsorption energy with Zn metal to avoid the side reaction with H2O and I3− and restrain the growth of Zn dendrites.