Interlayer Doping in Layered Vanadium Oxides for Low‐cost Energy Storage: Sodium‐ion Batteries and Aqueous Zinc‐ion Batteries

Abstract

Advantages concerns about abundant resources, low cost and high safety have promoted sodium‐ion batteries (SIBs) and aqueous zinc‐ion batteries (AZIBs) as the most promising candidates for next generation of low‐cost large‐scale energy storage. However, the state‐of‐the‐art cathode materials are far from meeting the commercial requirements. Considering the unique open framework, layered vanadium oxides have attracted wide attention due to the high energy density and power density, while they also face critical issues such as low stability and sluggish diffusion kinetics. The interlayer doping defects, as the most common method modulating layered materials, are believed to solve these problems which will be highlighted in this review. Firstly, the characteristics and current states of various vanadium oxides in SIBs and AZIBs are summarized. Then, the research efforts related to different types of interlayer doping defects, including ionic, molecular doping, etc., are discussed. Finally, it is pointed out that it is not enough to merely achieve satisfactory performances. Hence, some perspectives about the deep understanding and interrelationship are provided for the subsequent rational design of defective layered vanadium oxides for low‐cost energy storage systems.

Regulating Intercalation of Layered Compounds for Electrochemical Energy Storage and Electrocatalysis

“…For example, alkali metal (Li + , Na + , K + ) and multivalent metal ion (Mg 2+ , Mn 2+ , Ca 2+ , Al 3+ ) are introduced to pre-intercalation transition metal oxides, sulfide and selenide such as MoO 3 , MnO 2 , V 2 O 5 , MoS 2 and WS 2 , Bi 2 Se 3 , which could modify their layered structures and properties. [17,18,47] Koski et al have intercalated several zero-valent guest species (Co, Cu, Fe, In, Ni, Sn) using solution disproportionation redox reaction or carbonyl decomposition methods. [47] In addition, some intercalants come from solvents such as nitromethane and tetramethylene sulfone, dimethyl sulfoxide (DMSO) and alkylamine with different molecular length via the solution-based chemical intercalation technique.…”

“…For example, alkali metal (Li + , Na + , K + ) and multivalent metal ion (Mg 2+ , Mn 2+ , Ca 2+ , Al 3+ ) are introduced to pre‐intercalation transition metal oxides, sulfide and selenide such as MoO 3 , MnO 2 , V 2 O 5 , MoS 2 and WS 2 , Bi 2 Se 3 , which could modify their layered structures and properties. [ 17,18,47 ] Koski et al. have intercalated several zero‐valent guest species (Co, Cu, Fe, In, Ni, Sn) using solution disproportionation redox reaction or carbonyl decomposition methods.…”

“…Examples of successful guest species contain alkali metals ions (Li + , Na + and K + ), some transition metals (Cu, Co, Ni, Fe and Mn), and organic molecules or ions. [17][18][19][20][21][22] In this review, we comprehensively summarize the intercalation strategies of typical layered materials such as graphite, vanadium oxides, manganese dioxide, metal sulfides, and MXenes. The extensive applications of intercalated compounds in prevailing electrochemical energy storage and conversion, including lithium/sodium ion batteries, zinc battery, supercapacitor, and water splitting are thoroughly discussed (Figure 1).…”

“…Examples of successful guest species contain alkali metals ions (Li + , Na + and K + ), some transition metals (Cu, Co, Ni, Fe and Mn), and organic molecules or ions. [ 17–22 ]…”

Recent Developments of Preintercalated Cathodes for Rechargeable Aqueous Zn‐Ion Batteries

“…[ 29 ] Preincorporating of guest species into cathode can enhance the inherent cyclic stability from the atomic scale, and has been widely used as one of the most effective strategies in ZIBs. [ 30,31 ] The alien species can play a role of “pillar” to enlarge the diffusion channel and stabilize the host structure, which prevents the structure collapse and facilitates Zn 2+ ‐ion diffusion during the cycle process, leading to the improvement of cycling stability as well as rate capability. [ 32 ]…”