Potassium ion achieves high efficiency through battery
Supercapacitors come as an alternative to lithium-ion batteries, offering higher energy density and longer life (number of cycles of capacity maintained). A supercapacitor is like a cross between a battery (high power saving) and a conventional capacitor (with high power output).
New research from Hong Kong City University was released on March 21st Nanotechnology research energy Shows the best performance of a capacitor built with MXene compounds. MXenes are two-dimensional mineral compounds whose large molecular surface areas provide superior conductivity and storage capacity for energy storage.
Supercapacitors can store more energy in a smaller space and release more current; For example, it can supply power to mini devices such as wearable electronics. However, when made of organic molecules, supercapacitors are at risk of igniting.
The new study examined supercapacitors made of the mineral MXene molecules to reduce fire risk. They used potassium instead of expensive lithium. Potassium ion or K-ion is one of the most frequently used electrolytes to allow current to flow through a cell. Guojin Liang, the paper’s lead author and researcher in the field of material science and engineering, says, “They explored aqueous supercapacitors using intrinsically safe water-based electrolytes and focused on K-ion storage, which is cheaper and more cost-effective to use on Earth.”
MXenes compounds consist of multi-atom-thick layers of transition metals such as metal carbides, nitrides or carbonide. Electrical properties of efficient electron transport across the conductive metal carbide layer and excellent metal surface for redox (electron transfer) reactions.
Of the different MXenes, this study selected three to compare performance. “By horizontally comparing the K-ion storage performance of the three representative MXene species, we would like to find a correlation between the structure and their K-ion storage performance,” said Jinliang Li, a leading author in the field of Materials Science and Engineering. .
Three MXene Electrodes or Electrical Conductors-Nb2C, D23C2Investigated for their electrochemical behavior, including the chemistry of how K-ions are inserted in MXene layers and how ions adhere to metal surfaces. The researchers evaluated the supercapacitors’ storage mechanism, capacity, rate efficiency and rotation efficiency.
K-ion capacitor with Nb2The C MXene had the best performance at 2336 W / kg high energy density (discharged volume) and 24.6 Wh / kg energy density (stored volume). While lithium-ion batteries have a higher energy density than capacitors, their energy density is only at 250-340 W / kg. A K-ion capacitor with MXene, therefore, can quickly discharge quantity power orders. Capacitor with Nb2The C MXene maintained almost full capacity (94.6%) after 30,000 cycles of discharge of 5 ampere / g power, as opposed to the approximately 500 cycles the lithium-ion battery was expected to last.
All MXene products exhibit supercapacitor behavior – fast dynamics and durable K-ion storage – providing better performance than other K-ion host products. As potassium ions are obtained, the results are derived from the stable structure of MXene. Liang says, “This may be due to the large intermediate distance inherent to K-ion transport and the excellent structural stability of the MXene, which is subject to a long-term potassium / depotization process.”
Although only three MXene electrodes have been explored, other MXene compounds may have great potential to act as aqueous K-ion host electrodes. The researchers hope that their findings will “attract more attention to other promising MXene electrodes for durable K-ion storage.”
The researchers plan to experiment further with MXene electrodes towards improved performance for practical applications. “As for the K-ion capacitor, we want to modify and manipulate the MXene electrode species for higher energy density,” says Professor Suni Shi. They want to upgrade K-ion capacitors for wearable electronics and other mini power devices because they are more efficient, safer and relatively inexpensive.
<div class="article-main__explore my-4 d-print-none"> Creating high performance MXene electrodes for the next generation powerful battery </div> <hr class="mb-4"/> <div class="article-main__more p-4"> <strong>More info:</strong> Yi-Chun Lu et al., Design techniques for low temperature aqueous electrolytes, <i>Nanotechnology research energy</i> (2022) <a data-doi="1" href="https://dx.doi.org/10.26599/NRE.2022.9120003" target="_blank" rel="noopener">DOI: 10.26599 / NRE.2022.9120003</a> </div> <p> Contributed by Tsinghua University Press <!-- print only --> <div class="d-none d-print-block"> <strong>Quote</strong>: Achieving Potassium Ion Battery High Performance (April 14, 2022) Retrieved April 14, 2022 from https://phys.org/news/2022-04-higher-potassium-ion-battery.html This document is subject to copyright. No part may be reproduced without written permission, except for any reasonable manipulation for the purpose of personal study or research. Content is provided for informational purposes only. </div> </div>https://connect.facebook.net/en_US/sdk.js</p>