Layered Oxide Cathodes Promoted by Structure Modulation Technology for Sodium‐Ion Batteries

Abstract

Considering the ever‐growing climatic degeneration, sustainable and renewable energy sources are needed to be effectively integrated into the grid through large‐scale electrochemical energy storage and conversion (EESC) technologies. With regard to their competent benefit in cost and sustainable supply of resource, room‐temperature sodium‐ion batteries (SIBs) have shown great promise in EESC, triumphing over other battery systems on the market. As one of the most fascinating cathode materials due to the simple synthesis process, large specific capacity, and high ionic conductivity, Na‐based layered transition metal oxide cathodes commonly suffer from the sluggish kinetics, multiphase evolution, poor air stability, and insufficient comprehensive performance, restricting their commercialization application. Here, this review summarizes the recent advances in layered oxide cathode materials for SIBs through different optimal structure modulation technologies, with an emphasis placed on strategies to boost Na+ kinetics and reduce the irreversible phase transition as well as enhance the store stability. Meanwhile, a thorough and in‐depth systematical investigation of the structure–function–property relationship is also discussed, and the challenges as well as opportunities for practical application electrode materials are sketched. The insights brought forward in this review can be considered as a guide for SIBs in next‐generation EESC.

Recent advance in structure regulation of high‐capacity Ni‐rich layered oxide cathodes

“…Therefore, researchers desire to explore cathode materials with outstanding energy density, which undoubtedly relies on the material breakthroughs. [145][146][147][148][149][150][151] In the last few years, Ni-rich cathodes bring a huge prospect due to high discharging capacity and mass energy density, which is much higher than those of conventional positive materials (LiCoO 2 , LiFePO 4 , etc.). Although Ni-rich cathode materials exhibit an appealing advantage in EV market, it still undergoes unnecessary weaknesses such as inherent volume stress, cathode-electrolyte interface side reaction upon Li + insertion/extraction process.…”

Probing the charged state of layered positive electrodes in sodium-ion batteries: reaction pathways, stability and opportunities

“…147 A table of known biphasic and multiphasic layered oxide materials along with their respective electrochemical performances can be found in ref. 148.…”

Covalent Organic Frameworks for Next‐Generation Batteries

“…In addition, the reaction potential of sodium (À 2.71 V for Na/Na + ) is almost equivalent to that of lithium (À 3.04 V for Li/Li + ). [44][45][46][47][48] However, the energy density and cycle stability of SIBs are far inferior to those of LIBs. The main reason is that the radius of sodium ions is much larger than that of lithium ions, which causes large volume changes of the electrode materials during the charging and discharging process and leads to structural damage.…”