Re-oxidation reconstruction process of solid electrolyte interphase layer derived from highly active anion for potassium-ion batteries

In our work, we obtain molybdenum sulfide-reduced graphene oxide (MS-RGO) composite and find that variation of anion in electrolyte could significantly affect the stability of MS-RGO composite for potassium-ion batteries (KIBs). Here, our MS-RGO composite presents a high capacity of 328 mAh g(-1) at 50 mA g(-1) after 50 cycles and a stable capacity of 170 mAh g(-1) after 500 cycles even at 1 A g(-1). We find that the anion of bisfluorosulfimide (FSI) in electrolyte can significantly improve the cycling stability compared with anion of hexafluorophosphate (PF). The excellent performance of battery in FSI-containing electrolyte should be attributed to the enhanced re-oxidation reconstruction process of solid electrolyte interphase (SEI) layer. The imperceptible re-oxidation reconstruction process of SEI layer under the effect of anion can be detected by differential capacitance analysis in each cycle. Meanwhile, we also confirm that the reaction activity of anion is a critical factor in determining the reconstruction process of SEI layer and the improvement of electrochemical performance. The enhanced re-oxidation reconstruction process derived from highly active anion not only complements existing knowledge on the failure mechanism of SEI layer, but also presents a new principle for electrolyte design to improve the performance of metal sulfides anodes for KIBs.

Simultaneous Regulation on Solvation Shell and Electrode Interface for Dendrite-Free Zn Ion Batteries Achieved by a Low-Cost Glucose Additive

Dendrite growth and by-products in Zn metal aqueous batteries have impeded their development as promising energy storage devices. We utilize a low-cost additive, glucose, to modulate the typical ZnSO4 electrolyte system for improving reversible plating/stripping on Zn anode for high-performance Zn ion batteries (ZIBs). Combing experimental characterizations and theoretical calculations, we show that the glucose in ZnSO4 aqueous environment can simultaneously modulate solvation structure of Zn2+ and Zn anode-electrolyte interface. The electrolyte engineering can alternate one H2O molecule from the primary Zn2+-6H(2)O solvation shell and restraining side reactions due to the decomposition of active water. Concomitantly, glucose molecules are inclined to absorb on the surface of Zn anode, suppressing the random growth of Zn dendrite. As a proof of concept, a symmetric cell and Zn-MnO2 full cell with glucose electrolyte achieve boosted stability than that with pure ZnSO4 electrolyte.

In Situ Monitoring Small Energy Storage Change of Electrochromic Supercapacitors via Perovskite Photodetectors

In situ monitoring the healthy state of energy storage devices is a smart way to avoid severe accidents and major emergencies. Electrochromic supercapacitors (ECSCs) stand out among other devices owing to the smart color variation during charge and discharge processes. However, it is hard to obtain the precise state of charge via only identifying their color change. To address this problem, an integral system composed of the inorganic CsPbBr3 perovskite photodetector (PPD) and polyaniline (PANI)//WO3 ECSC is proposed here. The PPD can simultaneously collect the variation of responsive current (under a green laser with the wavelength of 520 nm) when the ECSC is being charged or discharged. The real-time state of charge following the color change can be recorded by the PPDs constantly and accurately. A voltage alteration as small as 47.2 mV (charge variation of 0.33 mC) can be detected by this integral system rapidly, implying its great potential in managing the health condition of ECSC or even common energy storage devices in the future.

Unveiling the electrochromic mechanism of Prussian Blue by electronic transition analysis

Prussian blue (PB) represents a class of metal-organic coordinated compounds with fascinating electrochromic properties. Although the electronic structure has been studied intensively, its electrochromic mechanism remains unresolved due to the lack of electronic-transition analysis. Herein, we investigate the electrochromism of Prussian blue (PB) and its derivatives by combining optical characterization and density functional theory (DFT) calculations. We unambiguously determine the optical gaps of PB-related derivatives and construct a smart window exhibiting excellent electrochromic performance and temperature control. DFT calculations demonstrate that the coloring of Prussian yellow (PY) is critically governed by two absorption bands centered at ca. 2.4 eV and 3.0 eV respectively. The former is weak and is generated by the charge-transfer transitions from the Fe(I)-t(2g) (Fe ions connected with C) band to the Fe(II)-t(2g) (Fe ions connected with N) band. The latter is strong and is induced by the electronic excitations from the Fe(I)-t(2g) band to the antibonding Fe(II)-eg band. The color change from yellow to blue is induced by the reduction of Fe(I) ions, which redshifts and enhances the former transitions but suppresses the latter transitions. In contrast, the color change from blue to transparency (Prussian white) is induced by the reduction of Fe(II) ions, which enlarges the bandgap and permits transmittance of visible light. The band-edge transition oscillator strengths are critically governed by the state weight of C-p, which provides opportunities for optical modulation via anionic doping. The insights obtained in this work are fundamental for understanding and controlling the opto-electronic properties of PB-related compounds for intelligent applications.

Stretchable Ni@NiCoP textile for wearable energy storage clothes

A Flexible Microsupercapacitor with Integral Photocatalytic Fuel Cell for Self-Charging

Reliable Information Encryption and Digital Display Applications Based on Multistate Smart Windows

In situ plasmonic optical fiber detection of the state of charge of supercapacitors for renewable energy storage

Rational design of carbon shell endows TiN@C nanotube based fiber supercapacitors with significantly enhanced mechanical stability and electrochemical performance

Visualized UV Photodetectors Based on Prussian Blue/TiO2 for Smart Irradiation Monitoring Application

Electrochromic Asymmetric Supercapacitor Windows Enable Direct Determination of Energy Status by the Naked Eye

Tailorable pseudocapacitors for energy storage clothes

All-solid-state tailorable supercapacitors based on flexible carbon nanotube (CNT)–polymer and CNT–metal oxide hybrid electrodes are successfully demonstrated.

Flexible honeycomb-like NiMn layered double hydroxide/carbon cloth architecture for electrochemical energy storage

WO3 nanoflowers with excellent pseudo-capacitive performance and the capacitance contribution analysis

WO3 nanoflower based negative electrodes demonstrate excellent balance between areal and gravimetric specific capacitances.

Tailorable and Wearable Textile Devices for Solar Energy Harvesting and Simultaneous Storage

Electrochromic energy storage devices

Energy storage devices with the smart function of changing color can be obtained by incorporating electrochromic materials into battery or supercapacitor electrodes. In this review, we explain the working principles of supercapacitors, batteries, and electrochromic devices. In addition, we discuss the material candidates for electrochromic energy storages in detail. The challenges of the integrated electrochromic energy system for simultaneous realization of electrochromism and energy storage are specially highlighted.

Ultrafast‐Charging Supercapacitors Based on Corn‐Like Titanium Nitride Nanostructures

Nickel oxide nanoflake-based bifunctional glass electrodes with superior cyclic stability for energy storage and electrochromic applications

We report the fabrication of NiO nanoflake-based bifunctional glass electrodes that combine energy storage and electrochromism.

Quantitative Analysis of Charge Storage Process of Tungsten Oxide that Combines Pseudocapacitive and Electrochromic Properties

Freestanding CNT–WO3 hybrid electrodes for flexible asymmetric supercapacitors

The CNT//CNT–WO3 asymmetric supercapacitor reaches a power density of 30.6 mW cm−3 and retains 75.8% after 50 000 cycles.

Significantly enhanced robustness and electrochemical performance of flexible carbon nanotube-based supercapacitors by electrodepositing polypyrrole

Large-Scale Fabrication of Pseudocapacitive Glass Windows that Combine Electrochromism and Energy Storage