Recent Advances in Mn‐Rich Layered Materials for Sodium‐Ion Batteries

Abstract

Branded with low cost and a high degree of safety, with an ambitious aim of substituting lithium-ion batteries in many fields, sodium-ion batteries have received fervid attention in recent years after being dormant for decades. Layered materials are a major focus of study owing to the extensive experience already gained in lithium-ion batteries, and the pursuit of a Mn-rich composition is critical to reduce the cost while retaining the performance. This review provides a timely update of the recent progress of Mn-rich layered materials for sodium-ion batteries based on the understandings of the phase forming principles, structure transformation upon cycling and charge compensation mechanisms and discusses potential ambiguities in the pursuit of high-performance materials.

A Universal Strategy Based on Bridging Microstructure Engineering and Local Electronic Structure Manipulation for High-Performance Sodium Layered Oxide Cathodes

“…The particle size and morphology of as-synthesized NaNi 0.5 Mn 0.48 Sn 0.02 O 2 (NaNMS-0.02), NaNi 0.5 Mn 0.45 Sn 0.05 O 2 (NaNMS-0.05), NaNi 0.5 Mn 0.4 Sn 0.1 O 2 (NaNMS-0.1), NaNi 0.5 Mn 0.3 Sn 0.2 O 2 (NaNMS-0.2), and NaNi 0.5 Mn 0.2 Sn 0.3 O 2 (NaNMS-0.3) materials were observed by scanning electron microscopy (SEM) (Figure a–f and Figure S1). The morphology of all as-prepared materials are blocky particles, and their particle size gradually becomes smaller with the increase of Sn content, as illustrated in the schematic diagram. , The concept of manipulating the morphology of the material allows precise tailoring of the microstructure through versatile chemical substitution strategies to obtain a stable structure . The increased particle size can reduce the contact area with the electrolyte and limit side reactions.…”

“…49,50 The concept of manipulating the morphology of the material allows precise tailoring of the microstructure through versatile chemical substitution strategies to obtain a stable structure. 51 The increased particle size can reduce the contact area with the electrolyte and limit side reactions. However, oversized particles can lead to a larger diffusion path for Na + during cycling.…”

Practical Cathodes for Sodium‐Ion Batteries: Who Will Take The Crown?

“…It should be noted that, unlike LIBs with a high‐Ni and Co‐free cathode, the optimal compositions of the cathode materials for SIBs have not yet been determined. [ 133 ] Based on the high voltage provided by Fe and Cr, high capacity provided by Ni, high electronic conductivity provided by Co, and good structural stability provided by Mn and Cu, researchers have developed a series of single (NaCrO 2 ), binary (Mn/Ni and Mn/Fe‐based oxides), ternary (MnNiCo, NiMnFe and FeMnCu systems), and multi‐metal oxides. [ 134 ]…”

First-Principles Studies on the Structural and Electronic Properties of α-Na2FePO4F with Strong Antisite Disorder

“…Cathodes can affect the power density of SIBs by influencing the ability to accommodate sodium ions and the smoothness of the transport channels. 9,10 Moreover, the depletion of the Na + active material and the impurity content also affect the lifetime of the battery. Lastly, the Na + and high redox potential of SIBs will play a crucial role in determining the operating voltage and reversible capacity of the battery.…”

“…Lithium-ion batteries (LIBs) have received a great deal of attention due to their relatively long cycle life, high theoretical capacity, and desirable rate capability. − However, sodium-ion batteries (SIBs) have advantages in resources and cost, so it has great potential to become a substitute for LIBs. − The energy storage capacity of SIBs depends greatly on the cathode material. Cathodes can affect the power density of SIBs by influencing the ability to accommodate sodium ions and the smoothness of the transport channels. , Moreover, the depletion of the Na + active material and the impurity content also affect the lifetime of the battery. Lastly, the Na + and high redox potential of SIBs will play a crucial role in determining the operating voltage and reversible capacity of the battery. − Therefore, the development of high-performance cathode materials (e.g., high redox potential, fast charge transfer and high capacity) is an important part of current SIB research. , Currently, cathode materials of SIBs mainly include transition-metal oxides, polyanionic compounds, Prussian blue derivatives, and organic compounds .…”