Crystal Facet and Architecture Engineering of Metal Oxide Nanonetwork Anodes for High-Performance Potassium Ion Batteries and Hybrid Capacitors

Abstract

Metal oxides are considered as prospective dual-functional anode candidates for potassium ion batteries (PIBs) and hybrid capacitors (PIHCs) because of their abundance and high theoretic gravimetric capacity; however, due to the inherent insulating property of wide band gaps and deficient ion-transport kinetics, metal oxide anodes exhibit poor K+ electrochemical performance. In this work, we report crystal facet and architecture engineering of metal oxides to achieve significantly enhanced K+ storage performance. A bismuth antimonate (BiSbO4) nanonetwork with an architecture of perpendicularly crossed single crystal nanorods of majorly exposed (001) planes are synthesized via CTAB-mediated growth. (001) is found to be the preferential surface diffusion path for superior adsorption and K+ transport, and in addition, the interconnected nanorods gives rise to a robust matrix to enhance electrical conductivity and ion transport, as well as buffering dramatic volume change during insertion/extraction of K+. Thanks to the synergistic effect of facet and structural engineering of BiSbO4 electrodes, a stable dual conversion-alloying mechanism based on reversible six-electron transfer per formula unit of ternary metal oxides is realized, proceeding by reversible coexistence of potassium peroxide conversion reactions (KO2↔K2O) and Bi x Sb y alloying reactions (BiSb ↔ KBiSb ↔ K3BiSb). As a result, BiSbO4 nanonetwork anodes show outstanding potassium ion storage in terms of capacity, cycling life, and rate capability. Finally, the implementation of a BiSbO4 nanonetwork anode in the state-of-the-art full cell configuration of both PIBs and PIHCs shows satisfactory performance in a Ragone plot that sheds light on their practical applications for a wide range of K+-based energy storage devices. We believe this study will propose a promising avenue to design advanced hierarchical nanostructures of ternary or binary conversion-type materials for PIBs, PIHCs, or even for extensive energy storage.

Recent Progress on Sb‐ and Bi‐based Chalcogenide Anodes for Potassium‐Ion Batteries

“…[10] Recently, many researchers invested tremendous efforts to exploit high specific capacity and long cycle life span host materials which can be classified into several categories including intercalation carbon-based materials (graphite, soft carbon, hard carbon, graphene), metal chalcogenides (MCs), metal and metal oxide. [11][12][13][14][15][16][17] Among them, MCs with different crystal structure has attracted a lot of attention because of their high theoretical capacity and earthabundant element resources. MCs, including sulfides, selenides, and tellurides, possess a wide range of properties and are of interest due to their high theoretical capacity and abundant elemental resources on earth.…”

Dimensional engineering of anode materials for high performance potassium ion hybrid capacitor—A review

“…Second, the high aspect ratio geometry enables 1D nanostructured materials to be crosslinked into different high‐dimensional networks and to form flexible materials for wearable PIHC devices 47,48 . Among them, 1D nanostructured materials deposited on a 2D plane to form regular array structures have been studied extensively recently, including ZnO, CuO, Zn‐Ni‐Co oxide (ZNCO), etc 49‐52 .…”

“…46 Second, the high aspect ratio geometry enables 1D nanostructured materials to be crosslinked into different high-dimensional networks and to form flexible materials for wearable PIHC devices. 47,48 Among them, 1D nanostructured materials deposited on a 2D plane to form regular array structures have been studied extensively recently, including ZnO, CuO, Zn-Ni-Co oxide (ZNCO), etc. [49][50][51][52] 1D nanostructured materials allow the electrolyte to penetrate into the electrode materials more easily, thus promoting charge transfer and obtaining higher power and so on.…”

“…Therefore, TMO and TMD 2D crystal plane structure engineering plays a very important role in potassium ion storage capacity. 47,91 Xu et al used the insitu directional growth method to construct ultra-thin MOF (ZIF-8) interface layer on 2D black phosphorus (BP) nanosheets denoted as BPNS@MOF (Figure 5A, C). 14 The prepared composite has ordered nanopore protective layer and good structural stability, which is conducive to efficient transportation of potassium ions, while is able to adapt to volume changes in the cycle process.…”

“…However, transition metal compounds have limited application in PIHC anode materials due to their inherent band gap width and ion transport kinetics defects. Therefore, TMO and TMD 2D crystal plane structure engineering plays a very important role in potassium ion storage capacity 47,91 . Xu et al used the in‐situ directional growth method to construct ultra‐thin MOF (ZIF‐8) interface layer on 2D black phosphorus (BP) nanosheets denoted as BPNS@MOF (Figure 5A,C).…”