Manganese‐based polyanionic cathodes for sodium‐ion batteries

Abstract

Owing to abundant resources and low cost, sodium‐ion batteries (SIBs) are sweeping the world at a rapid pace. The cathode is the key to determining the energy density of the battery, and polyanionic compounds have become a representative class of cathode materials due to their stable three‐dimensional framework structure, high operating voltage, and good safety. Vanadium‐based and iron‐based polyanionic compounds are highly regarded in academic communities, but environmental hazards or low energy densities have once overshadowed them in the practical arena. In contrast, manganese (Mn)‐based polyanion is one of the potential candidates in terms of cost, voltage, and environmental friendliness, besides, many noteworthy advances have been recorded in recent years. This review summarizes the current research progress of Mn‐based polyanions and discusses the challenges they face while looking forward to the future development of such materials and ideas to solve the key problems. It is expected to have a positive effect, that is, to attract more practitioners to focus on the practical way out of such materials.

Reactive boride as a multifunctional interface stabilizer for garnet-type solid electrolyte in all-solid-state lithium batteries

“…25 Inspired by their pioneering work, we attempted to use cobalt boride as a multifunctional layer coated on an as-prepared pristine LLZTO solid-state electrolyte. 33–39 Besides, according to the previous reports, Co x B has a relatively wide band gap between the valence band and conduct band. This intrinsic nature of Co x B can show a satisfactory electronic blocking ability when used as a functional coating layer as well.…”

Novel Alkaline Sodium-Ion Battery Capacitor Based on Active Carbon||Na0.44MnO2 towards Low Cost, High-Rate Capability and Long-Term Lifespan

“…The cathode and anode active substances of ion batteries are compounds that can be reversibly extraction/insertion. It has high energy density, but the power density is insufficient and the cycle life is short, which restricts the development of the battery 3,4 . Electrochemical capacitors with high power density and long cycle life are known as an important supplement to batteries in electrical energy storage applications [5][6][7] .…”

Sodium Layered/Tunnel Intergrowth Oxide Cathodes: Formation Process, Interlocking Chemistry, and Electrochemical Performance

“…One of the main concerns regarding the practical application of SIBs is to find outstanding electrode materials, especially cathode materials, which determine the critical battery characteristics such as specific capacity, rate performance, and cyclic stability. – Recently, great efforts have been devoted to developing excellent cathode materials including layered transitional metal oxides (Na x TMO 2 ), Prussian-blue analogues, and polyanion compounds. – Among them, Na x TMO 2 ( x ≤ 1, TM = transition metal), particularly Mn-based oxides have been mostly exploited because of their low cost, easy synthesis, high specific capacity, high energy density, and environmental friendliness. – Typically, Na x TMO 2 can be divided into layered and tunnel structures. There are four main kinds of layered structures including O2, O3, P2, and P3 types according to classification depending on their Na occupation sites and the stacking sequence of O layers. – Compared with O3-type oxides, the P2-type materials exhibit better rate performance owing to large prismatic residing sites and facile diffusion paths for Na + . – So far, many P2-type sodium layered oxides have been explored as cathode materials for SIBs, such as Na 0.67 MnO 2 , Na 0.67 Fe 0.5 Mn 0.5 O 2 , Na 0.55 [Ni 0.1 Fe 0.1 Mn 0.8 ]­O 2 , Na 0.67 [Mg 0.28 Mn 0.72 ]­O 2 , Na 0.67 Mn 0.6 Ni 0.3 Cu 0.1 O 2 , Na 0.72 [Li 0.24 Mn 0.76 ]­O 2 , etc.…”