2023 roadmap for potassium-ion batteries

The heavy reliance of lithium-ion batteries (LIBs) has caused rising concerns on the sustainability of lithium and transition metal and the ethic issue around mining practice. Developing alternative energy storage technologies beyond lithium has become a prominent slice of global energy research portfolio. The alternative technologies play a vital role in shaping the future landscape of energy storage, from electrified mobility to the efficient utilization of renewable energies and further to large-scale stationary energy storage. Potassium-ion batteries (PIBs) are a promising alternative given its chemical and economic benefits, making a strong competitor to LIBs and sodium-ion batteries for different applications. However, many are unknown regarding potassium storage processes in materials and how it differs from lithium and sodium and understanding of solid–liquid interfacial chemistry is massively insufficient in PIBs. Therefore, there remain outstanding issues to advance the commercial prospects of the PIB technology. This Roadmap highlights the up-to-date scientific and technological advances and the insights into solving challenging issues to accelerate the development of PIBs. We hope this Roadmap aids the wider PIB research community and provides a cross-referencing to other beyond lithium energy storage technologies in the fast-pacing research landscape

蓄電池応用を目指したカリウムインサーション材料および電解液に関する研究

東京理科大学2020年

Mechanochemical Synthesis of K<i>_x</i>Mn[Fe(CN)₆] and CNT Composite for High-power Potassium-ion Batteries (Supporting Information)

This study introduces a facile mechanochemical synthesis of KxMn[Fe(CN)6] (KMnHCF) and carbon nanotube (CNT) composite (KMnHCF@CNT) as a positive electrode material for potassium-ion batteries. The KMnHCF@CNT, synthesized by a simultaneous process of mechanochemical synthesis and carbon compositing, shows a homogeneous composite and achieves a much higher electron conductivity of 7.16 × 10−1 S cm−1 than the KMnHCF and CNT mixture (2.35 × 10−2 S cm−1) synthesized by the two-step process. The improved electron conductivity demonstrates reduced carbon content in the electrode and excellent rate performance of maintaining 80 mAh g−1 at 20 C in potassium cells.</p

Mg-Doped KFeSO₄F as a High-Performance Cathode Material for Potassium-Ion Batteries

Potassium iron sulfate fluoride (KFeSO4F) is a high-voltage positive electrode material for potassium-ion batteries, but its practical performance remains limited due to its moderate electronic conductivity. In this study, we employed Mg ion doping in the Fe site of KFeSO4F to tune the crystallinity and ionic/electronic conductivity. Furthermore, we made a composite with carbon nanotubes to enhance the electrode’s electronic conductivity. In a K-ion cell filled with concentrated potassium bis(fluorosulfonyl)amide/triglyme electrolyte, the KFe0.95Mg0.05SO4F/CNT composite electrode delivers discharge (potassiation) capacities of 107 and 100 mAh g–1 in the first and 100th cycles at a rate of 0.1C with reasonable rate capability. UV–vis absorption spectroscopy studies of Mg-doped KFeSO4F powder samples showed a narrower band gap compared to KFeSO4F. Furthermore, from the combined results of X-ray diffraction and absorption spectroscopy studies, we found that multiple two-phase reaction mechanisms through the Fe3+/Fe2+ redox occurred during the reversible depotassiation/potassiation cycle

Application of Diluted Electrode Method to Sodium-ion Insertion into Hard Carbon Electrode

Herein, the diluted-electrode method is applied to a hard carbon (HC) electrode to estimate sodium-ion (Na+) insertion kinetics. As metallic nickel (Ni) particles do not accommodate Na+ ions in the potential range of 0–2.0 V vs. Na+/Na, the HC powder electrode is diluted by adding inert Ni particles, enabling the adjustment of the HC concentration while maintaining the composite electrode structure. By examining the rate capabilities of the HC electrodes with different dilutions, we confirm that the Na+ insertion rate for the highly diluted electrode is 10 times higher than that for the undiluted electrode. These improved kinetics can be attributed to the alleviation of Na+ depletion, which results in insignificant concentration polarization under dilute conditions. For a highly diluted electrode, the Na+ insertion kinetics must be controlled by the Na+ mobility in the HC particles and across the HC/electrolyte interface. Therefore, our study reveals that the inherent kinetics of Na+ insertion into HC is very high and provides a basis for developing high-power Na-ion batteries

2023 Roadmap on molecular modelling of electrochemical energy materials

New materials for electrochemical energy storage and conversion are the key to the electrification and sustainable development of our modern societies. Molecular modelling based on the principles of quantum mechanics and statistical mechanics as well as empowered by machine learning techniques can help us to understand, control and design electrochemical energy materials at atomistic precision. Therefore, this roadmap, which is a collection of authoritative opinions, serves as a gateway for both the experts and the beginners to have a quick overview of the current status and corresponding challenges in molecular modelling of electrochemical energy materials for batteries, supercapacitors, CO2 reduction reaction, and fuel cell applications

2023 roadmap for potassium-ion batteries

The heavy reliance of lithium-ion batteries (LIBs) has caused rising concerns on the sustainability of lithium and transition metal and the ethic issue around mining practice. Developing alternative energy storage technologies beyond lithium has become a prominent slice of global energy research portfolio. The alternative technologies play a vital role in shaping the future landscape of energy storage, from electrified mobility to the efficient utilization of renewable energies and further to large-scale stationary energy storage. Potassium-ion batteries (PIBs) are a promising alternative given its chemical and economic benefits, making a strong competitor to LIBs and sodium-ion batteries for different applications. However, many are unknown regarding potassium storage processes in materials and how it differs from lithium and sodium and understanding of solid–liquid interfacial chemistry is massively insufficient in PIBs. Therefore, there remain outstanding issues to advance the commercial prospects of the PIB technology. This Roadmap highlights the up-to-date scientific and technological advances and the insights into solving challenging issues to accelerate the development of PIBs. We hope this Roadmap aids the wider PIB research community and provides a cross-referencing to other beyond lithium energy storage technologies in the fast-pacing research landscape