Printing is regarded as a revolutionary and feasible technique to guide the fabrication of versatile functional systems with designed architectures. 2D MXenes are nowadays attractive in printed ...energy storage devices. However, owing to the van der Waals interaction between the MXene layers, the restacking issues within the printed electrodes can significantly impede the ion/electrolyte transport and hence handicap the electrochemical performances. Herein, a melamine formaldehyde templating method is demonstrated to develop crumpled nitrogen‐doped MXene (MXene‐N) nanosheets. The nitrogen doping boosts the electrochemical performances of MXene via enhanced conductivity and redox activity. Accordingly, two types of MXene‐N inks are prepared throughout the optimization of the ink viscosity to fit the 2D screen printing and 3D extrusion printing, respectively. As a result, the screen printed MXene‐N microsupercapacitor delivers an areal capacitance of 70.1 mF cm−2 and outstanding mechanical robustness. Furthermore, the 3D‐printed MXene‐N based supercapacitor manifests an areal capacitance of 8.2 F cm−2 for a three‐layered electrode and readily stores a high areal energy density of 0.42 mWh cm−2. The approach to harnessing such versatile MXene‐N inks offers distinctive insights into the printed energy storage systems with high areal energy density and large scalability.
Versatile N‐doped MXene inks with different viscosities are designed to accommodate multidimensional printing techniques toward the construction of printed energy storage devices, readily displaying favorable areal capacity and energy density.
Zinc metal anode has garnered a great deal of scientific and technological interest. Nevertheless, major bottlenecks restricting its large‐scale utilization lie in the poor electrochemical stability ...and unsatisfactory cycling life. Herein, a Janus separator is developed via directly growing vertical graphene (VG) carpet on one side of commercial glass fiber separator throughout chemical vapor deposition. A simple air plasma treatment further renders the successful incorporation of oxygen and nitrogen heteroatoms on bare graphene. Thus‐derived 3D VG scaffold affording large surface area and porous structure can be viewed as a continuation of planar zinc anode. In turn, the Janus separator harvests homogenous electric field distribution and lowered local current density at the interface of the anode/electrolyte, as well as harnesses favorable zincophilic feature for building‐up uniform Zn ionic flux. Such a separator engineering enables an impressive rate and cycle performance (93% over 5000 cycles at 5 A g−1) for Zn‐ion hybrid capacitors and outstanding energy density (182 Wh kg−1) for V2O5//Zn batteries, respectively. This strategy with large scalability and cost‐effectiveness represents a universal route to protect prevailing metal anodes (Zn, Na, K) in rechargeable batteries.
A directly grown vertical graphene carpet on one side of a commercial glass fiber separator affords an evenly distributed electric field, lowered local current density, and boosted zincophilic effect, thereby enabling a Janus separator toward stabilized Zn anodes.
3D printing technology has stimulated a burgeoning interest to fabricate customized architectures in a facile and scalable manner targeting wide ranged energy storage applications. Nevertheless, ...3D-printed hybrid capacitor devices synergizing favorable energy/power density have not yet been explored thus far. Herein, we demonstrate a 3D-printed sodium-ion hybrid capacitor (SIC) based on nitrogen-doped MXene (N-Ti3C2T x ) anode and activated carbon cathode. N-Ti3C2T x affording a well-defined porous structure and uniform nitrogen doping can be obtained via a sacrificial template method. Thus-formulated ink can be directly printed to form electrode architecture without the request of a conventional current collector. The 3D-printed SICs, with a large areal mass loading up to 15.2 mg cm–2, can harvest an areal energy/power density of 1.18 mWh cm–2/40.15 mW cm–2, outperforming the state-of-the-art 3D-printed energy storage devices. Furthermore, our SIC also achieves a gravimetric energy/power density of 101.6 Wh kg–1/3269 W kg–1. This work demonstrates that the 3D printing technology is versatile enough to construct emerging energy storage systems reconciling high energy and power density.
Potassium‐ion hybrid capacitors (KICs) reconciling the advantages of batteries and supercapacitors have stimulated growing attention for practical energy storage because of the high abundance and low ...cost of potassium sources. Nevertheless, daunting challenge remains for developing high‐performance potassium accommodation materials due to the large radius of potassium ions. Molybdenum diselenide (MoSe2) has recently been recognized as a promising anode material for potassium‐ion batteries, achieving high capacity and favorable cycling stability. However, KICs based on MoSe2 are scarcely demonstrated by far. Herein, a diatomite‐templated synthetic strategy is devised to fabricate nitrogen‐doped MoSe2/graphene (N‐MoSe2/G) composites with favorable pseudocapacitive potassium storage targeting a superior anode material for KICs. Benefiting from the unique biomorphic structure, high electron/K‐ion conductivity, enriched active sites, and the conspicuous pseudocapacitive effect of N‐MoSe2/G, thus‐derived KIC full‐cell manifests high energy/power densities (maximum 119 Wh kg−1/7212 W kg−1), outperforming those of recently reported KIC counterparts. Furthermore, the potassium storage mechanism of N‐MoSe2/G composite is systematically explored with the aid of first‐principles calculations in combination of in situ X‐ray diffraction and ex situ Raman spectroscopy/transmission electron microscopy/X‐ray photoelectron spectroscopy.
Nitrogen‐doped MoSe2/graphene composites prepared via a biotemplated strategy are employed as highly effective anodes for potassium‐ion hybrid capacitors, manifesting high energy/power density (119 Wh kg−1/7212 W kg−1) and long lifespan.
Wearable and portable self-powered units have stimulated considerable attention in both the scientific and technological realms. However, their innovative development is still limited by inefficient ...bulky connections between functional modules, incompatible energy storage systems with poor cycling stability, and real safety concerns. Herein, we demonstrate a flexible solar-charging integrated unit based on the design of printed magnesium ion aqueous asymmetric supercapacitors. This power unit exhibits excellent mechanical robustness, high photo-charging cycling stability (98.7% capacitance retention after 100 cycles), excellent overall energy conversion and storage efficiency (η
= 17.57%), and outstanding input current tolerance. In addition, the Mg ion quasi-solid-state asymmetric supercapacitors show high energy density up to 13.1 mWh cm
via pseudocapacitive ion storage as investigated by an operando X-ray diffraction technique. The findings pave a practical route toward the design of future self-powered systems affording favorable safety, long life, and high energy.
Sodium ion batteries (SIBs) are considered the most promising battery technology in the post‐lithium era due to the abundant sodium reserves. In the past two decades, exploring new electrolytes for ...SIBs has generally relied on the “solid electrolyte interphase (SEI)” theory to optimize the electrolyte components. However, many observed phenomena cannot be fully explained by the SEI theory. Therefore, electrolyte solvation structure and electrode–electrolyte interface behavior have recently received tremendous research interest to explain the improved performance. Considering there is currently no review paper focusing on the solvation structure of electrolytes in SIBs, a systematic survey on SIBs is provided, in which the specific solvation structure design guidelines and their consequent impact on the electrochemical performance are elucidated. The key driving force of solvation structure formation, and the recent advances in adjusting SIB solvation structures are discussed in detail. It is believed that this review can provide new insights into the electrolyte optimization strategies of high‐performance SIBs and even other emerging battery systems.
This review focuses on the solvation structure of electrolytes in sodium ion batteries, elucidating the specific solvation structure design guidelines and their consequent impact on the electrochemical performance. The key driving force of solvation structure formation, and the recent advances in adjusting sodium ion battery solvation structures are discussed in detail.
Mass production of graphene powders affording high quality and environmental benignancy serves as a prerequisite for the practical usage of graphene in multiple energy storage applications. Herein, ...we exploit a salt-templated CVD approach to harness the direct synthesis of nitrogen-doped graphene (NG) nanosheets and related ink dispersions in a scalable, safe, efficient, and green fashion. Thus-fabricated NG accompanying large productivity, excellent electrical conductivity, and favorable solution processability possesses implications in printable energy storage devices. With the NG-based ink in hand, self-standing 3D architectures with programmable patterns can be directly printed over a myriad of substrates. Accordingly, both electrode preparation for flexible supercapacitors and separator modification in Li–S batteries can be enabled via printing by employing our NG-based composite inks. This work thus represents a practical route for mass production of graphene inks with cost-effectiveness and eco-friendliness for emerging energy storage technology.
The booming of wearable electronics has nourished the progress on developing multifunctional energy storage systems with versatile flexibility, which enable the continuous and steady power supply ...even under various deformed states. In this sense, the synergy of flexible energy and electronic devices to construct integrative wearable microsystems is meaningful but remains quite challenging by far. Herein, we devise an innovative supercapacitor/sensor integrative wearable device that is based upon our designed vanadium nitride-graphene (VN-G) architectures. Flexible quasi-solid-state VN-G supercapacitor with ultralight and binder-free features deliver a specific capacitance of ~ 53 F·g
−1
with good cycle stability. On the other hand, VN-G derived pressure sensors fabricated throughout a spray-printing process also manifest favorably high sensitivity (40 kPa
−1
at the range of 2–10 kPa), fast response time (~ 130 ms), perfect skin conformability, and outstanding stability under static and dynamic pressure conditions. In turn, their complementary unity into a self-powered wearable sensor enables the precise detection of physiological motions ranging from pulse rate to phonetic recognition, holding promise for in-practical health monitoring applications.
Aqueous zinc (Zn) ion batteries (AZIBs) are regarded as one of the promising candidates for next‐generation electrochemical energy storage systems due to their low cost, high safety, and ...environmental friendliness. However, the commercialization of AZIBs has been severely restricted by the growth of dendrite at the Zn metal anode. Tailoring the planar‐structured Zn anodes into three‐dimensional (3D) structures has proven to be an effective way to modulate the plating/stripping behavior of Zn anodes, resulting in the suppression of dendrite formation. This review provides an up‐to‐date review of 3D structured Zn metal anodes, including working principles, design, current status, and future prospects. We aim to give the readers a comprehensive understanding of 3D‐structured Zn anodes and their effective usage to enhance AZIB performance.
This review systematically discusses the progress of advanced 3D structural Zn anodes, including preparation methods, surface composition modifications, gradient structure designs, and side reaction inhibitions. The article also concludes by outlining the existing challenges and prospects for further developing high‐performance 3D structural Zn anodes.
Solar energy is one of the most popular clean energy resources that can be fully utilized to date. The growing energy demand of modern society has spurred the technological advance of solar cells ...affording high power conversion efficiency and low-cost aspects. Nevertheless, the intrinsically intermittent nature and fluctuating output power of solar irradiation greatly restrain the practical uses of solar cells, especially in the scenarios of smart consumer electronics, electrical vehicles and hydrogen fuel production. With a collection of attractive features including favorable stability, durability and practicability, solar-driven integrated energy system that synergizes energy harvesting and storage offer a viable solution. This review summarizes the state-of-the-art knowledge in designing concepts, integrated configurations and overall performances of different types of solar-driven hybrid energy units. Particular attentions are paid to highlighting the practical application sectors enabled by those integrated energy systems. Future perspectives and key challenges in this emerging field are also covered at the end.
•State-of-the-art designs of solar-driven hybrid energy units are summarized.•Overall performances and practical applications are highlighted.•Future perspectives and key challenges in this realm are discussed.
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