Ag-Zn Batteries Research Articles

Roughened Graphite Collector Coupled with Hydrolysis‐Resistance Zinc Chloride Electrolyte Enables Large‐Size Rechargeable Ag–Zn Battery

AbstractAg–Zn batteries have the advantages of being a high‐safety and stable discharge platform but still face challenges such as high cost, electrolyte hydrolysis, and zinc dendrites. In this study, a low‐cost roughness graphite paper (GP) enables more uniform loaded Ag particles to construct Ag/rough graphite paper (Ag/RGP) cathode with high wettability of low‐concentration ZnCl2 electrolyte, achieving both capacity and reversibility enhancement. Both a few additions of citric acid (CA) to the low‐concentration ZnCl2 electrolyte can also inhibit the hydrolysis of Zn2+ and increase the nucleation overpotential due to suitable acidity and complexation ability, resulting in more even Zn deposited behavior on low‐cost Zn foil anode. Meanwhile, the ZnCl2‐CA electrolyte can also promote redox reaction and thus improve the capacity of the Ag/RGP cathode. As a result, the assembled large‐size Ag–Zn battery (50 cm2) with low‐cost Ag/RGP and low‐concentration ZnCl2‐CA obtains a capacity of 0.76 mAh cm−2 at a current density of 0.4 mA cm−2, with a cycle life of ≈100% capacity retention over 50 cycles, also easily powering a LED array and displaying high practicability. This work provides a feasible and practical route to fabricate large‐size and low‐cost Ag–Zn batteries.

Decoupled tin-silver batteries with long cycle life and power output stability based on dendrite-free tin anode and halide insertion cathode chemistry.

Conventional Ag-Zn batteries have historically faced the challenge of poor cycling stability, rooting in issues associated with Ag cathode dissolution and Zn anode dendrites. Herein, we present a pioneering decoupled Sn-Ag cell, which features two chambers separated by a cation-exchange membrane, containing a dendrite-free Sn metal anode immersed in an alkaline anolyte, and an Ag nanowires/carbon nanotube 3D thick-network cathode in a neutral catholyte. Benefiting from the achieved high electroplating/stripping stability of the metallic Sn anode in the alkaline electrolyte and the electrochemical reversibility of the Ag/AgCl cathode redox couple in the neutral electrolyte, the assembled decoupled Sn-Ag cell demonstrates superior cycling stability, retaining 82.4% of its initial capacity even after 4000 cycles (2 mA cm-2), significantly outperforming both the contrastive decoupled Ag-Zn cell (1500 cycles) and conventional alkaline Ag-Zn batteries (<100 cycles). Furthermore, through the integration of the decoupled Sn-Ag battery with solar cells and power management circuits, an intelligent power system of photovoltaic charging and energy storage was designed, demonstrating its practical viability through maintenance-free charging-discharging during day-night cycles. This research not only significantly increases the lifespan of Ag-batteries with an ultra-flat voltage platform but also opens avenues for the decoupled design of a wide variety of aqueous battery systems.

Long-Life flexible mild Ag-Zn fibrous battery with bifunctional gel electrolyte

Silver-zinc (Ag-Zn) fibrous batteries are considered as a promising power source for next-generation flexible/wearable electronics because of their superior safety, high energy density, and stable output voltage. Nevertheless, the widespread application of Ag-Zn batteries is hindered by their limited cycle life, primarily caused by Zn dendrite growth and Ag migration. Herein, we develop a flexible mild Ag-Zn fibrous battery with outstanding cycle performance via designing a bifunctional gel electrolyte. The graphene oxide (GO) introduced into the electrolyte provides dual enhancement in suppressing the growth of Zn dendrite and migration of Ag, leading to improved structural integrity and long cycle life. The designed fibrous battery demonstrates a high capacity of 0.85 mAh cm−1 and it can retain 90% (77.4%) of the initial capacity after 250 cycles under current density of 0.5 (5) mA cm−1. Additionally, the battery can maintain its performance under various deformations and a four-battery set is employed as the power source for LED patterns and wearable sensors. This work provides a rational way to design advanced gel electrolytes for high-performance flexible batteries.

A self-healable silk fibroin-based hydrogel electrolyte for silver-zinc batteries with high stability

Due to the intrinsic safety, mechanical flexibility and cost-effectiveness, aqueous batteries with hydrogel electrolytes are particularly advantageous for wearable electronics. Herein, a self-healable silk fibroin-based hydrogel electrolyte with semi-interpenetrating network structure was developed, which possesses both high ionic conductivity (14.4 mS cm−1) and excellent mechanical strength. The supramolecular hydrogen bonding interaction between the amide bond and the polypeptide of silk fibroin enables the hydrogel electrolyte with superior self-healable capability, which largely improves the interfacial compatibility between electrode and electrolyte, thus suppressing the growth of Zn dendrites. The resultant Ag-Zn battery delivers a high capacity of 110 mAh g−1 at 0.5 A g−1 with good cycling stability of 85.7% capacity retention after 800 cycles.

High Areal Capacity and Long Cycle Life Flexible Mild Quasi‐Solid‐State Ag–Zn Battery with Dendrite‐Free Anode

Silver‐zinc (Ag–Zn) batteries are a promising battery system for flexible electronics owing to their high safety, high energy density, and stable output voltage. However, poor cycling performance, low areal capacity, and inferior flexibility limit the practical application of Ag–Zn batteries. Herein, we develop a flexible quasi‐solid‐state Ag–Zn battery system with superior performance by using mild electrolyte and binder‐free electrodes. Copper foam current collector is introduced to impede the growth of Zn dendrite, and the structure of Ag cathode is engineered by electrodeposition and chloridization process to improve the areal capacity. This novel battery demonstrates a remarkable cycle retention of 90% for 200 cycles at 3 mA cm−2. More importantly, this binder‐free battery can afford a high capacity of 3.5 mAh cm−2 at 3 mA cm−2, an outstanding power density of 2.42 mW cm−2, and a maximum energy density of 3.4 mWh cm−2. An energy management circuit is adopted to boost the output voltage of a single battery, which can power electronic ink display and Bluetooth temperature and humidity sensor. The developed battery can even operate under the extreme conditions, such as being bent and sealed in solid ice. This work offers a path for designing electrodes and electrolyte toward high‐performance flexible Ag–Zn batteries.

3D Printed Stretchable Liquid Gallium Battery

AbstractDespite the rapid progress on soft and stretchable batteries, current fabrication techniques involve manual disposition and stencil/screen printing. Here, for the first time, a 3D‐printed Ag–Ga battery is introduced through subsequent printing of four sinter‐free composites: a stretchable Liquid Metal (LM) EGaIn‐Ag‐Styrene‐isoprene block copolymers (SIS), and Carbon‐SIS current collectors; Ag2O‐SIS cathode; and a novel Ga‐C‐SIS anode. Being sinter‐free results in faster printing, and compatibility with heat‐sensitive substrates. Although the Ga‐C‐SIS is solid‐like and nonsmearing after printing, it creates a liquid interface after contacting with the electrolyte. This results in a self‐feeding and self‐aggregation mechanism that brings more gallium to the surface and delays the formation of the dead surface. The record‐breaking areal capacity of ≈19.4 mAh cm−2, along with excellent stretchability (&gt;130% Max. strain), makes the Ag–Ga battery an excellent alternative to Ag–Zn batteries. Surprisingly, digital printing results in 3x higher areal capacity compared to stencil printing, due to greater gallium exposure at the surface. The desired voltage and current output can be customized by printing several battery cells and interconnect them in series/parallel. Also, printing of sensors, electrodes, batteries, and interconnects on a biomonitoring e‐textile for simultaneous monitoring of electrocardiography, body temperature, and respiration is demonstrated.

Ultra-durable and flexible fibrous mild quasi-solid-state Ag–Zn batteries with Na2SO4electrolyte additive

The synergistic effect of Cl−ion stabilizing the Ag cathode , the Na+ion regulating the Zn deposition and the flexibility of carbon nanotube fibers endows fibrous quasi-solid-state mild Ag–Zn batteries with admirable durability and flexibility.

A high-performance flexible aqueous silver–zinc rechargeable battery based on AgNP/CNT-graphite paper and ZnNF-graphite paper

The flexibility and safety of energy storage devices have drawn wide attention due to rapid development of wearable electronics. Silver-zinc (Ag–Zn) battery are one of the promising aqueous zinc-based battery with non-toxic environment, stable output voltage and high energy density. Flexible electrode plays a key role in excellent mechanical and electrochemical properties of batteries. In this work, silver nanoparticles/carbon nanotubes-graphite paper (AgNP/CNT-Gp) cathode is prepared by double-side coating on graphite paper. The mixed silver nanoparticles and carbon nanotubes construct a 3D spatial conductive network to contribute excellent electrochemical performance for Ag–Zn battery. The quasi-solid-state Ag–Zn battery shows area specific capacity of 1.268 mAh/cm2 and excellent energy density of 1.913 mWh/cm2 at current density of 1 mA/cm2. The battery not only represents superior electrochemical properties, but also demonstrates perfect flexibility. We use the quasi-solid-state Ag–Zn battery to successfully light up an indicator composed of 9 LED bulbs, which can still work when the battery is completely folded.

Commencing mild Ag–Zn batteries with long-term stability and ultra-flat voltage platform

Alkaline Silver (Ag)-Znic (Zn) batteries have been suffering from poor cyclic stability for over one century but the comprehensively improving protocol is still in vacancy with big challenge. Here, we commence a mild Ag–Zn battery to simultaneously solve the cathode dissolving issue and anode dendrite issue. The battery proceeds through anionic halides as charging carriers for cathode reactions, endowing two phase transition process with ultra-flat discharging voltage plateau. The battery delivered unprecedently elongated cyclic lifetime to 1300 cycles in contrast to conventional alkaline Ag–Zn battery (<100 cycles). This work not only solved the long-term cyclic issue of Ag–Zn battery but also would act as a model system to introduce mild electrolyte and anionic charging carriers into other aqueous battery systems for performance improvement.

(Invited) Improvements in High Energy Density Silver-Zinc Button Cells for Wearable Devices

The silver (Ag)-zinc (Zn) system has the highest theoretical specific (Wh/kg) and volumetric energy density (Wh/L) amongst all rechargeable batteries with the added benefit of safety and non-flammability compared to lithium-ion or lithium metal batteries, which makes it a good and ideal candidate for portable applications like hearing-aids. However, historically, the Ag-Zn battery has suffered from poor rechargeability and low energy utilization. At ZPower, we have tailored the chemistry and engineered a new Ag-Zn battery system, which is highly energy dense and rechargeable, thus making it possible to use it portable applications and giving more power to the consumer to allow them to contribute to a greener future. As aforementioned, enhancing the capacity of the active materials is paramount for high energy density, which we achieved by developing proprietary additives and methods. For the cathode, silver oxide (AgO) was used in our system. We developed novel proprietary conductive coatings for AgO, which allowed high capacity utilization and retention for many cycles. We conducted gassing tests, where we found the coatings considerably reduced oxygen generation. The role of these coatings was further studied through charge algorithm cycling, where we found that it reduced AgO cathode’s impedance compared to the control tests and maintained its active surface area. More importantly, we found that the morphology of the proprietary conductive coatings played a crucial role in efficiently utilizing the AgO cathode’s capacity. For the anode, Zn was used, where it has a theoretical specific capacity of 820 mAh/g; however, Zn has a long history of poor rechargeability due to problems like shape change (zinc redistribution), dendrite formation and passivation. In the past, previous researchers tried altering the Zn formulation to increase utilization; however, these attempts were not fruitful. We have engineered a new Zn anode that can access 94% of its theoretical capacity in a single primary discharge and 56% of its theoretical capacity rechargeably for over 300 cycles. We achieved this breakthrough by developing proprietary additives and methods that localize the Zn to the current collector and prevent dendrite formation. We will comment on the anode performance further in the talk. Finally, we will present impedance models and data of the ZPower Ag-Zn system measured with respect to state of charge, storage time and temperature, which is vital from a manufacturing standpoint to understand cell properties and make future cell and electrode improvements. We will comment on our future work of identifying impedance contribution from the cathode and anode components of the battery and using this data as a guideline for improving electrode composition and cell performance.

Autocatalytic Metallization of Fabrics Using Si Ink, for Biosensors, Batteries and Energy Harvesting.

Commercially available metal inks are mainly designed for planar substrates (for example, polyethylene terephthalate foils or ceramics), and they contain hydrophobic polymer binders that fill the pores in fabrics when printed, thus resulting in hydrophobic electrodes. Here, a low‐cost binder‐free method for the metallization of woven and nonwoven fabrics is presented that preserves the 3D structure and hydrophilicity of the substrate. Metals such as Au, Ag, and Pt are grown autocatalytically, using metal salts, inside the fibrous network of fabrics at room temperature in a two‐step process, with a water‐based silicon particle ink acting as precursor. Using this method, (patterned) metallized fabrics are being enabled to be produced with low electrical resistance (less than 3.5 Ω sq−1). In addition to fabrics, the method is also compatible with other 3D hydrophilic substrates such as nitrocellulose membranes. The versatility of this method is demonstrated by producing coil antennas for wireless energy harvesting, Ag–Zn batteries for energy storage, electrochemical biosensors for the detection of DNA/proteins, and as a substrate for optical sensing by surface enhanced Raman spectroscopy. In the future, this method of metallization may pave the way for new classes of high‐performance devices using low‐cost fabrics.

High-Performance Quasi-Solid-State Flexible Aqueous Rechargeable Ag–Zn Battery Based on Metal–Organic Framework-Derived Ag Nanowires

Silver–zinc (Ag–Zn) batteries are one of the promising aqueous batteries to collect and store solar energy with high energy density, a stable output voltage, and being environmentally benign, but most Ag–Zn batteries have large contact resistance caused by polymer binders and conductive additives, thus leading to their low specific capacity and rate performance. As a proof-of-concept demonstration, we constructed a solar charged planar flexible quasi-solid-state aqueous rechargeable Ag–Zn battery using metal–organic framework (MOF)-derived Ag nanowires on carbon cloth as a binder-free cathode. Our electrochemical results show that the as-fabricated Ag–Zn battery has a remarkable energy density of 1.87 mWh/cm2 because MOF-derived Ag nanowires can provide abundant reaction sites and short electron and ion diffusion paths. Moreover, the as-fabricated Ag–Zn battery integrated with a solar cell can be charged by sunlight. Thus, our findings pave an avenue to develop solar energy-powered portable and wearable e...

(Invited) Capabilities and Opportunities for Next-Generation Ag–3D Zn Batteries

Silver–zinc batteries offer high specific energy (up to 190 Wh kg–1) and the highest specific power of any known commercial battery (up to 600 W kg–1 continuous power and 2,500 W kg–1 pulses). The Ag–Zn system operates using water-based electrolytes and nonhazardous active materials, providing an ideal battery alternative to Li-ion (flammable; explosive) and Pb-acid (toxic) in the diverse markets where these drawbacks must be avoided. Despite the many advantages of Ag–Zn batteries, adoption beyond specialized applications is hindered by a Zn anode that accesses only middling zinc specific capacity and has limited rechargeability. We have recently overcome these hurdles by developing a monolithic Zn sponge electrode that exhibits cycling durability in prototype Ni–Zn cells and a 50% greater specific capacity in Zn–air cells, both relative to the same systems that use conventional powder-bed Zn electrodes. The cathodes used in those chemistries are ill-equipped to counter-balance the specific power that the Zn sponge has to offer. Silver–zinc presents higher power and energy density than Ni–Zn batteries and a more market-ready cathode than Zn–air, making Ag–3D Zn an attractive battery chemistry with which to demonstrate the triumvirate of rechargeability, high specific energy, and high specific power. We present prototype Ag–3D Zn cells that discharge to record-breaking extreme depths-of-Zn-discharge, support rechargeability rarely seen in the Ag–Zn system, and can operate at 104–105 W kgZn –1. Toward the goal of developing next-generation Ag–3D Zn batteries, we also describe our breakthroughs and existing challenges in: (i) the design of full cell Ag–3D Zn prototypes; (ii) the fabrication of beta 2.0 Zn sponges with tunable density; and (iii) the preparation of AgxO cathodes that support the high performance of Zn sponge anodes.

Chronic ovine evaluation of a totally implantable electrical left ventricular assist system.

The totally implantable Novacor left ventricular assist system (LVAS) comprises a pump/drive unit (VAD), electronic control and power subsystem (ECP), variable volume compensator (VVC), and belt skin transformer (BST). The system is now undergoing chronic in vivo evaluation. Cumulative animal testing of VAD, VVC, and BST subsystems are 12.1, 4.9, and 43 years, respectively. The longest implants were 279 days for the VAD, 767 days for the VVC, and 1,148 days for the BST. A chronic implant of the total system was electively terminated at 260 days. The LVAS was powered via the BST. Continuously monitored hemodynamic and pump parameters have demonstrated normal hemodynamics and LVAS operation. Periodic VVC determinations suggest a 0.8 ml/day diffusive gas loss. Tether-free operation has been demonstrated with an Ag-Zn battery backpack. The animal was healthy and free of infection as indicated by routine hematologic, biochemical and serum enzyme determinations. Hemolysis is minimal (plasma free hemoglobin less than 5 mg%). Pump output ranged from 7 to 8 L/min. Severe valve calcification was the reason for elective termination at 260 days. This preclinical in vivo experience, and in vitro reliability studies, demonstrate efficacy of the total system.

Chronic Ovine Evaluation of a Totally Implantable Electrical Left Ventricular Assist System

The totally implantable Novacor left ventricular assist system (LVAS) comprises a pump/drive unit (VAD), electronic control and power subsystem (ECP), variable volume compensator (VVC), and belt skin transformer (BST). The system is now undergoing chronic in vivo evaluation. Cumulative animal testing of VAD, VVC, and BST subsystems are 12.1, 4.9, and 43 years, respectively. The longest implants were 279 days for the VAD, 767 days for the VVC, and 1,148 days for the BST. A chronic implant of the total system was electively terminated at 260 days. The LVAS was powered via the BST. Continuously monitored hemodynamic and pump parameters have demonstrated normal hemodynamics and LVAS operation. Periodic VVC determinations suggest a 0.8 ml/day diffusive gas loss. Tether-free operation has been demonstrated with an Ag-Zn battery backpack. The animal was healthy and free of infection as indicated by routine hematologic, biochemical and serum enzyme determinations. Hemolysis is minimal (plasma free hemoglobin <5 mg%). Pump output ranged from 7 to 8 L/min. Severe valve calcification was the reason for elective termination at 260 days. This preclinical in vivo experience, and in vitro reliability studies, demonstrate efficacy of the total system.