The performances of rechargeable batteries are strongly affected by the operating environmental temperature. In particular, low temperatures (e.g., ≤0 °C) are detrimental to efficient cell cycling. ...To circumvent this issue, we propose a few-layer Bi
Se
(a topological insulator) as cathode material for Zn metal batteries. When the few-layer Bi
Se
is used in combination with an anti-freeze hydrogel electrolyte, the capacity delivered by the cell at -20 °C and 1 A g
is 1.3 larger than the capacity at 25 °C for the same specific current. Also, at 0 °C the Zn | |few-layer Bi
Se
cell shows capacity retention of 94.6% after 2000 cycles at 1 A g
. This behaviour is related to the fact that the Zn-ion uptake in the few-layer Bi
Se
is higher at low temperatures, e.g., almost four Zn
at 25 °C and six Zn
at -20 °C. We demonstrate that the unusual performance improvements at low temperatures are only achievable with the few-layer Bi
Se
rather than bulk Bi
Se
. We also show that the favourable low-temperature conductivity and ion diffusion capability of few-layer Bi
Se
are linked with the presence of topological surface states and weaker lattice vibrations, respectively.
Conventional charge storage mechanisms for electrode materials are common in widely exploited insertion/extraction processes, while some sporadic examples of chemical conversion mechanisms exist. It ...is perceived to be of huge potential, but it is quite challenging to develop new battery chemistry to promote battery performance. Here, an initiating and holistic deposition–dissolution battery mechanism for both cathodes and anodes is reported. A MnO2–Cu battery based on this mechanism demonstrates outstanding energy density (27.7 mWh cm−2), power density (1232 mW cm−2), high reversibility, and unusual Coulombic efficiency. It can be charged to 0.8 mAh cm−2 within 42 s and possessees a stable rate cyclability within vastly varied discharging current density (4–64 mA cm−2). Moreover, the deposition–dissolution mechanism can be universally adopted and derived such that the corresponding MnO2–Zn and MnO2–Bi batteries are successfully constructed. The material selection principle, deposition–dissolution behaviors of cathode/anode materials, and battery performance are systematically elaborated. Since the electrodeposition chemistry is capable of involving a large family of materials, for example, metal oxides as cathode materials, or metals as anode materials, the research could be a model system to open a door to explore new aqueous battery materials and chemistry.
Deposition–dissolution mechanism is developed to design reversible aqueous batteries, which are verified as a universal principle by selecting MnO2 as cathode materials and three different metals (Cu, Zn, and Bi) as anode materials. The battery design process is elaborated and as‐fabricated batteries deliver impressive performance, such as stable rate performance, high energy density, and long‐term cyclic stability.
Stretchable devices need elastic hydrogel electrolyte as an essential component, while most hydrogels will lose their stretchability after being incorporated with strong alkaline solution. This is ...why highly stretchable zinc–air batteries have never been reported so far. Herein, super‐stretchable, flat‐ (800% stretchable) and fiber‐shaped (500% stretchable) zinc–air batteries are first developed by designing an alkaline‐tolerant dual‐network hydrogel electrolyte. In the dual‐network hydrogel electrolyte, sodium polyacrylate (PANa) chains contribute to the formation of soft domains and the carboxyl groups neutralized by hydroxyls as well as cellulose as potassium hydroxide stabilizer are responsible for vastly enhanced alkaline tolerance. The obtained super‐stretchable, flat zinc–air battery exhibits a high power density of 108.6 mW⋅cm−2, increasing to 210.5 mW⋅cm−2 upon being 800% stretched. Similar phenomena are observed for the 500% stretchable fiber‐shaped batteries. The devices can maintain stable power output even after being heavily deformed benefiting from the highly soft, alkaline‐tolerant hydrogel electrolyte developed. A bendable battery‐display system and water proof weavable fiber zinc–air battery are also demonstrated. This work will facilitate the progress of using zinc–air battery powering flexible electronics and smart clothes. Moreover, the developed alkaline‐tolerant super‐stretchable electrolyte can also be applied for many other alkaline electrolyte‐based energy storage/conversion devices.
An alkaline‐tolerant, dual‐network hydrogel electrolyte‐based sodium polyacrylate and cellulose is developed. The hydrogel infiltrated by 6 m KOH solution as electrolyte still shows over 1000% stretchability, together with a 0.28 S∙cm−1 ion conductivity. Super‐stretchable, flat‐ (800% stretchable) and fiber‐shaped (500% stretchable) zinc–air batteries with high electrochemical performance and mechanical flexibility are developed based on the hydrogel electrolyte.
The exploitation of a high-efficient, low-cost, and stable non-noble-metal-based catalyst with oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) simultaneously, as air electrode ...material for a rechargeable zinc–air battery is significantly crucial. Meanwhile, the compressible flexibility of a battery is the prerequisite of wearable or/and portable electronics. Herein, we present a strategy via single-site dispersion of an Fe–N x species on a two-dimensional (2D) highly graphitic porous nitrogen-doped carbon layer to implement superior catalytic activity toward ORR/OER (with a half-wave potential of 0.86 V for ORR and an overpotential of 390 mV at 10 mA·cm–2 for OER) in an alkaline medium. Furthermore, an elastic polyacrylamide hydrogel based electrolyte with the capability to retain great elasticity even under a highly corrosive alkaline environment is utilized to develop a solid-state compressible and rechargeable zinc–air battery. The creatively developed battery has a low charge–discharge voltage gap (0.78 V at 5 mA·cm–2) and large power density (118 mW·cm–2). It could be compressed up to 54% strain and bent up to 90° without charge/discharge performance and output power degradation. Our results reveal that single-site dispersion of catalytic active sites on a porous support for a bifunctional oxygen catalyst as cathode integrating a specially designed elastic electrolyte is a feasible strategy for fabricating efficient compressible and rechargeable zinc–air batteries, which could enlighten the design and development of other functional electronic devices.
Output voltage and self‐discharge rate are two important performance indices for supercapacitors, which have long been overlooked, though these play a very significant role in their practical ...application. Here, a zinc anode is used to construct a zinc ion hybrid capacitor. Expanded operating voltage of the hybrid capacitor is obtained with novel electrolytes. In addition, significantly improved anti‐self‐discharge ability is achieved. The phosphorene‐based zinc ion capacitor exploiting a “water in salt” electrolyte with a working potential can reach 2.2 V, delivering 214.3 F g−1 after 5000 cycles. The operating voltage is further extended to 2.5 V through the use of an organic solvent as the electrolyte; the solvent is prepared by adding 0.2 m ZnCl2 into the tetraethylammonium tetrafluoroborate in propylene carbonate (Et4NBF4/PC) solvent, and it exhibits 105.9 F g−1 even after 9500 cycles. More importantly, the phosphorene‐based capacitors possess excellent anti‐self‐discharge performance. The capacitors retain 76.16% of capacitance after resting for 300 h. The practical application of the zinc ion capacitor is demonstrated through a flexible paper‐based printed microcapacitor. It is believed that the developed zinc ion capacitor can effectively resolve the severe self‐discharge problem of supercapacitors. Moreover, high‐voltage zinc ion capacitors provide more opportunities for the application of supercapacitors.
Herein, a few‐layer phosphorene cathode is used to construct a zinc ion hybrid capacitor. Expanded operating voltage of the hybrid capacitor is obtained with novel electrolytes. In addition, significantly improved anti‐self‐discharge ability is achieved. The cathode materials exhibit outstanding cycling performance (214.3 F g−1 after 5000 cycles) and excellent anti‐self‐discharge performance (retaining 76.16% of capacitance after resting for 300 h).
Rechargeable Zn‐based batteries (RZBs) have attracted much attention and been regarded as one of the most promising candidates for next‐generation energy storage featured with high safety, low costs, ...environmental friendliness, and satisfactory energy density. The aqueous electrolyte system exhibits great potential to power the future wearable electronics. Apart from the achievements of high capacity cathode and stable electrolyte, the anode suffers from problems of dendrite growth, hydrogen evolution, and passivation with limited attention. The dendrite formation strongly restricts the battery lifespan. Therefore, strategies focused on dendrite suppression are carefully categorized and summarized in this review, including crystallographic orientation manipulation, electric field control, ion flux regulation, and mechanical shield. Each strategy and the detailed approaches are critically dissected. Finally, remaining challenges are emphasized in this review, expecting to supply further research with potential directions to fulfill the high performance of the Zn anodes.
Dendrites issues in aqueous rechargeable Zn‐based battery have aroused increasing attention recently. This review categorized from the main fundamental theory in suppression the zinc dendrites including crystallographic orientation manipulation, electric field control, ion flux regulation, and mechanical shield. Detail approaches under each category are discussed critically and further considerations are provided for future study.
Aqueous rechargeable metal‐ion batteries (ARMBs) represent one of the current research frontiers due to their low cost, high safety, and other unique features. Evolving to a practically useful ...device, the ARMBs must be adaptable to various ambient, especially the cold weather. While much effort has been made on organic electrolyte batteries operating at low temperatures, the study on low‐temperature ARMBs is still in its infancy. The challenge mainly comes from water freezing at subzero temperatures, resulting in dramatically retarded kinetics. Here, the freezing behavior of water and its effects on subzero performances of ARMBs are first discussed. Then all strategies used to enhance subzero temperature performances of ARMBs by associating them with battery kinetics are summarized. The subzero temperature performances of ARMBs and organic electrolyte batteries are compared. The final section presents potential directions for further improvements and future perspectives of this thriving field.
Based on the freezing behavior of water and its effects on subzero performances of aqueous rechargeable metal‐ion batteries (ARMBs), strategies used to enhance subzero performance of ARMBs by associating them with battery kinetics are summarized. The subzero performance of ARMBs and organic electrolyte batteries are compared. Future perspectives of this thriving field are presented.
While traditional three‐layer structure supercapacitors are under mechanical manipulations, the high‐stress region concentrates, inevitably causing persistent structural problems including interlayer ...slippage, crease formation, and delamination of the electrode–electrolyte interface. Toward this, an all‐polymeric, all‐elastic and non‐laminated supercapacitor with high mechanical reliability and excellent electrochemical performance is developed. Specifically, a polypyrrole electrode layer is in situ integrated into a silk fibroin‐based elastic supramolecular hydrogel film with extensive hydrogen and covalent bonds, where a non‐laminate device is realized with structural elasticity at the device level. The non‐laminate configuration can avoid slippage and delamination, while the elasticity can preclude crease formation. Furthermore, under more severe mechanical damage, the supercapacitors can restore the electrochemical performance through non‐autonomous self‐healing capabilities, where the supramolecular design of host–guest interactions in the hydrogel matrix results in a superior self‐healing efficiency approaching ≈95.8% even after 30 cutting/healing cycles. The all‐elastic supercapacitor delivers an areal capacitance of 0.37 F cm−2 and a volumetric energy density of 0.082 mW h cm−3, which can well‐maintain the specific capacitance even at −20 °C with over 85.2% retention after five cut/healing cycles.
An integrated all polymer‐based supercapacitor with superior reliability and durability is developed, which exhibits a self‐healing efficiency approaching 100% via supramolecular chemistry of host–guest interactions between β‐cyclodextrin and amino acid side chains of silk fibroin.
Electroluminescent (EL) devices have been extensively integrated into multi-functionalized electronic systems in the role of the vitally constituent light-emitting part. However, the lifetime and ...reliability of EL devices are often severely restricted by concomitant damage, especially when the strain exceeds the mechanical withstanding limit. We report a self-healable EL device by adopting a modified self-healable polyacrylic acid hydrogel as the electrode and a self-healable polyurethane as a phosphor host to realize the first omni-layer-healable light-emitting device. The physicochemical properties of each functionalized layer can be efficiently restored after experiencing substantial catastrophic damage. As a result, the luminescent performance of the self-healable EL devices is well recovered with a high healing efficiency (83.2% for 10 healing cycles at unfixed spots, and 57.7% for 20 healing cycles at a fixed spot). In addition, inter-device healing has also been developed to realize a conceptual "LEGO"-like assembly process at the device level for light-emitting devices. The design and realization of the self-healable EL devices may revive their performance and expand their lifetime even after undergoing a deadly cut. Our self-healable EL devices may serve as model systems for electroluminescent applications of the recently developed ionically conductive healable hydrogels and dielectric polymers.
With the advantages of benign mechanical property, electrochemical stability, and low cost, graphite fibers (GFs) have been widely used as electrodes for vanadium redox flow batteries (VRFBs). ...However, GFs usually possess inferior electrochemical activity and ion diffusion kinetics for electrode reaction, vastly limiting their application in VRFBs. Here, a 3D carbon nanonetwork coated GFs with multi-heteroatom doping was constructed for application in VRFBs via low temperature polymerization between linear polymer monomer and phytic acid, and subsequent carbonization (900 °C) on the GFs (GF@PCNs-900). Benefiting from the 3D structural features and multi-heteroatom doping (O, N and P), the composite electrode displayed sufficient diffusion of vanadium ions, rapid electron conduction, and highly enhanced electrochemical activity of reactive site on the electrodes. As a result, the GF@PCNs-900 delivered a high discharge capacity of 21 Ah L
and energy efficiency of above 70% with extraordinary stability during 200 cycles at 200 mA cm
. Even at a huge current density of 400 mA cm
, the GF@PCNs-900 still maintained a discharge capacity of 5.0 Ah L
, indicating an excellent rate of performance for VRFBs. Such design strategy opens up a clear view for further development of energy storage field.
PDF
