Showing papers by "Bing Ding published in 2022"

Amorphous and Porous Tungsten Oxide Films for Fast‐Switching Dual‐Band Electrochromic Smart Windows

Abstract: Dual‐band electrochromic smart windows with dynamic and independent control of near‐infrared (NIR) and visible (VIS) light transmittance can notably reduce the carbon footprint of buildings and improve the occupants’ visual and thermal comfort. The dual‐band response is often generated by the phase transition of crystalline electrochromic materials. However, the phase‐transition of crystalline materials is kinetically sluggish, resulting in a long response time. Herein, a fast‐switching dual‐band electrochromic smart window based on a single‐component amorphous and porous tungsten oxide (AP‐WO3) cathode without the slow phase‐transition process is demonstrated. The amorphous and porous structure of WO3 not only significantly improves the ion transport, but also provides a large surface area for Li+ adsorption that gives rise to a tunable surface plasmon resonance (SPR) in the NIR range. Consequently, the single‐component AP‐WO3 film can modulate the NIR and VIS light transmittance independently and effectively through three distinct modes with high optical modulation, fast switching speed, high bistability, and good cycling stability. The prototype dual‐band electrochromic device assembled by AP‐WO3 cathode also delivers an impressive dual‐band electrochromic performance with fast‐switching speed (6.4 s for coloration and 7.2 s for bleaching).

Novel Ionic Liquid-based Electrolyte Assisting the High Performance of Low-temperature Supercapacitors

Abstract: Tailoring electrolyte components is an effective solution for building supercapacitors that can provide stable performance at low temperature, where traditional energy storage devices fail to operate. In this work, we...

Theoretical and Experimental Understanding of Metal Single-Atom Electrocatalysts for Accelerating the Electrochemical Reaction of Lithium-Sulfur Batteries.

Abstract: Metal single-atom materials have attracted tremendous attention in the research field of lithium-sulfur (Li-S) batteries because they can effectively improve the reaction kinetics of sulfur cathodes. However, it is still difficult to determine the best metal single-atom catalyst for Li-S batteries, due to the lack of a unified measurement and evaluation method. Herein, a series of metal single-atom- and nitrogen-doped graphene materials (M-NG, M = Fe, Co, Ni, Ir, Ru) have been prepared as the catalysts for promoting the reaction kinetics of the sulfur reduction reaction process. Using rotating disk electrode measurements and density functional theory-based theoretical calculations, Ni-NG was screened out to be the best catalyst. It is found that Ni-NG materials can provide a kinetically favorable pathway for the reversible conversion of polysulfide conversion, thus increasing the utilization of sulfur. By coating the Ni-NG materials on the separator as a multifunctional interlayer, a commercially available sulfur cathode presents a stable specific capacity of 701.8 mAh g-1 at a current rate of 0.5C over 400 cycles. Even with a high sulfur loading of 3.8 mg cm-2, a high areal capacity of 4.58 mAh cm-2 can be achieved. This work will provide a fundamental understanding of efficient single-atom catalyst materials for Li-S batteries.

Long-Cycling All-Solid-State Batteries Achieved by 2D Interface between Prelithiated Aluminum Foil Anode and Sulfide Electrolyte.

Abstract: All-solid-state batteries (ASSBs) with alloy anodes are expected to achieve high energy density and safety. However, the stability of alloy anodes is largely impeded by their large volume changes during cycling and poor interfacial stability against solid-state electrolytes. Here, a mechanically prelithiation aluminum foil (MP-Al-H) is used as an anode to construct high-performance ASSBs with sulfide electrolyte. The dense Li-Al layer of the MP-Al-H foil acts as a prelithiated anode and forms a 2D interface with sulfide electrolyte, while the unlithiated Al layer acts as a tightly bound current collector and ensures the structural integrity of the electrode. Remarkably, the MP-Al-H anode exhibits superior lithium conduction kinetics and stable interfacial compatibility with Li6 PS5 Cl (LPSCl) and Li10 GeP2 S12 electrolytes. Consequently, the symmetrical cells using LPSCl electrolyte can work at a high current density of 7.5 mA cm-2 and endure for over 1500 h at 1 mA cm-2 . Notably, ≈100% capacity is retained for the MP-Al-H||LPSCl||LiCoO2 full cell with high area loadings of 18 mg cm-2 after 300 cycles. This work offers a pathway to improve the interfacial and performance issues for the application of ASSBs.

Fabrication of a Covalent Triazine Framework Functional Interlayer for High-Performance Lithium–Sulfur Batteries

Abstract: The shuttling effect of polysulfides is one of the major problems of lithium–sulfur (Li–S) batteries, which causes rapid capacity fading during cycling. Modification of the commercial separator with a functional interlayer is an effective strategy to address this issue. Herein, we modified the commercial Celgard separator of Li–S batteries with one-dimensional (1D) covalent triazine framework (CTF) and a carbon nanotube (CNT) composite as a functional interlayer. The intertwined CTF/CNT can provide a fast lithium ionic/electronic transport pathway and strong adsorption capability towards polysulfides. The Li–S batteries with the CTF/CNT/Celgard separator delivered a high initial capacity of 1314 mAh g−1 at 0.1 C and remained at 684 mAh g−1 after 400 cycles−1 at 1 C. Theoretical calculation and static-adsorption experiments indicated that the triazine ring in the CTF skeleton possessed strong adsorption capability towards polysulfides. The work described here demonstrates the potential for CTF-based permselective membranes as separators in Li–S batteries.