Multiscale factors in designing alkali-ion (Li, Na, and K) transition metal inorganic compounds for next-generation rechargeable batteries

Abstract

<p>The demand for ‘more energy and less carbon’ is one of the most important challenges facing humanity. Exploring not only more efficient renewable energy systems, but also advanced energy conversion...</p>

Insights into Layered Oxide Cathodes for Rechargeable Batteries

“…This is a critical feature of Li x MO 2 compounds that gives them high capacity in a relatively narrow voltage window compared to other alkali compounds, as explained below. The effective interaction between intercalating ions increases significantly when larger alkali ions (e.g., Na + and K + ) are used in the layered structure [ 41 , 42 , 43 ]. These larger alkali ions increase the oxygen slab distance, reducing the oxygen charge density available for screening within the alkali layer [ 20 , 42 , 43 ].…”

“…The effective interaction between intercalating ions increases significantly when larger alkali ions (e.g., Na + and K + ) are used in the layered structure [ 41 , 42 , 43 ]. These larger alkali ions increase the oxygen slab distance, reducing the oxygen charge density available for screening within the alkali layer [ 20 , 42 , 43 ]. The larger effective repulsion between the Na + or K + ions affects the phase transition and electrochemistry in a very significant way as shown in Figure 2 b.…”

Recent Progress and Prospects of Layered Cathode Materials for Potassium‐ion Batteries

“…The above three researchers are awarded the 2019 Nobel Prize in chemistry, because LIBs have been proven to be the most powerful technology for supplying high energy and power demands over the past 20 years. [9] Other layered materials, such as LiNi x Co y Mn 1-xy O 2 and xLiMO 2 Á(1-x)Li 2 MnO 3 (Li-rich cathode), with higher capacities and lower costs also attract much attention. [10] As a result of controllable synthesis, large capacities and energy densities, and relatively high electronic conductivities, layered transition metal oxides have been extensively studied in LIBs.…”

Aliovalent‐Ion‐Induced Lattice Regulation Based on Charge Balance Theory: Advanced Fluorophosphate Cathode for Sodium‐Ion Full Batteries

“…Sodium‐ion batteries (SIBs) have drawn extensive attention in electronic devices and energy storage systems over the recent years, [ 1 ] because of the ample distribution in the Earth's crust and low cost of Na resources as well as the analogical work principle to lithium‐ion batteries (LIBs). [ 2 ] However, due to the inherent defect of Na + with large ionic radius, cathode materials of SIBs are usually confronted with more challenges, such as sluggish ion diffusion kinetics and unappeasable structural stability, which are seriously hindering the future development of SIBs. [ 2b,3 ] Therefore, scientists are mainly dedicated to design cathode crystal lattice with high adaptability and reversibility during Na + de‐/intercalation processes.…”