Lab隨記: 2020

The rechargeable aluminum-ion battery (AIB) is a promising candidate for next-generation high-performance batteries, but its cathode materials require more development to improve their capacity and cycling life. We have demonstrated the growth of MoSe2 three-dimensional helical nanorod arrays on a polyimide substrate by the deposition of Mo helical nanorod arrays followed by a low-temperature plasma-assisted selenization process to form novel cathodes for AIBs. The binder-free 3D MoSe2-based AIB shows a high specific capacity of 753 mAh g–1 at a current density of 0.3 A g–1 and can maintain a high specific capacity of 138 mAh g–1 at a current density of 5 A g–1 with 10 000 cycles. Ex situ Raman, XPS, and TEM characterization results of the electrodes under different states confirm the reversible alloying conversion and intercalation hybrid mechanism during the discharge and charge cycles. All possible chemical reactions were proposed by the electrochemical curves and characterization. Further exploratory works on interdigital flexible AIBs and stretchable AIBs were demonstrated, exhibiting a steady output capacity under different bending and stretching states. This method provides a controllable strategy for selenide nanostructure-based AIBs for use in future applications of energy-storage devices in flexible and wearable electronics.

https://doi.org/10.1021/acsnano.0c02831

2020年6月30日星期二

Transparent Flexible Heteroepitaxy of NiO Coated AZO Nanorods Arrays on Muscovites for Enhanced Energy Storage Application

Transparent flexible energy storage devices are considered as important chains in the next‐generation, which are able to store and supply energy for electronic devices. Here, aluminum‐doped zinc oxide (AZO) nanorods (NRs) and nickel oxide (NiO)‐coated AZO NRs on muscovites are fabricated by a radio frequency (RF) magnetron sputtering deposition method. Interestingly, AZO NRs and AZO/NiO NRs are excellent electrodes for energy storage application with high optical transparency, high conductivity, large surface area, stability under compressive and tensile strain down to a bending radius of 5 mm with 1000 bending cycles. The obtained symmetric solid‐state supercapacitors based on these electrodes exhibit good performance with a large areal specific capacitance of 3.4 mF cm−2, long cycle life 1000 times, robust mechanical properties, and high chemical stability. Furthermore, an AZO/NiO//Zn battery based on these electrodes is demonstrated, yielding a discharge capacity of 195 mAh g−1 at a current rate of 8 A g−1 and a discharge capacity of over 1000 cycles with coulombic efficiency to 92%. These results deliver a concept of opening a new opportunity for future applications in transparent flexible energy storage.

https://doi.org/10.1002/smll.202000020

2020年5月4日星期一

High-Performance Rechargeable Aluminum–Selenium Battery with a New Deep Eutectic Solvent Electrolyte: Thiourea-AlCl3

Aluminum–sulfur batteries (ASBs) have attracted substantial interest due to their high theoretical specific energy density, low cost, and environmental friendliness, while the traditional sulfur cathode and ionic liquid have very fast capacity decay, limiting cycling performance because of the sluggishly electrochemical reaction and side reactions with the electrolyte. Herein, we demonstrate, for the first time, excellent rechargeable aluminum–selenium batteries (ASeBs) using a new deep eutectic solvent, thiourea-AlCl3, as an electrolyte and Se nanowires grown directly on a flexible carbon cloth substrate (Se NWs@CC) by a low-temperature selenization process as a cathode. Selenium (Se) is a chemical analogue of sulfur with higher electronic conductivity and lower ionization potential that can improve the battery kinetics on the sluggishly electrochemical reaction and the reduction of the polarization where the thiourea-AlCl3 electrolyte can stabilize the side reaction during the reversible conversion reaction of Al–Se alloying processes during the charge–discharge process, yielding a high specific capacity of 260 mAh g–1 at 50 mA g–1 and a long cycling life of 100 times with a high Coulombic efficiency of nearly 93% at 100 mA g–1. The working mechanism based on the reversible conversion reaction of the Al–Se alloying processes, confirmed by the ex situ Raman, XRD, and XPS measurements, was proposed. This work provides new insights into the development of rechargeable aluminum–chalcogenide (S, Se, and Te) batteries

https://pubs.acs.org/doi/10.1021/acsami.0c03882