Single‐Atom Tailored Hierarchical Transition Metal Oxide Nanocages for Efficient Lithium Storage

Abstract

Mitigating the mechanical degradation and enhancing the ionic/electronic conductivity are critical but challengeable issues toward improving electrochemical performance of conversion‐type anodes in rechargeable batteries. Herein, these challenges are addressed by constructing interconnected 3D hierarchically porous structure synergistic with Nb single atom modulation within a Co3O4 nanocage (3DH‐Co3O4@Nb). Such a hierarchical‐structure nanocage affords several fantastic merits such as rapid ion migration and enough inner space for alleviating volume variation induced by intragrain stress and optimized stability of the solid‐electrolyte interface. Particularly, experimental studies in combination with theoretical analysis verify that the introduction of Nb into the Co3O4 lattice not only improves the electron conductivity, but also accelerates the surface/near‐surface reactions defined as pesudocapacitance behavior. Dynamic behavior reveals that the ensemble design shows huge potential for fast and large lithium storage. These features endow 3DH‐Co3O4@Nb with remarkable battery performance, delivering ≈740 mA h g−1 after ultra‐long cycling of 1000 times under a high current density of 5 A g−1. Importantly, the assembled 3DH‐Co3O4@Nb//LiCoO2 pouch cell also presents a long‐lived cycle performance with only ≈0.059% capacity decay per cycle, inspiring the design of electrode materials from both the nanostructure and atomic level toward practical applications.

Synergistically Tailoring the Electronic Structure and Ion Diffusion of Atomically Thin Co(OH)2 Nanosheets Enable Fast Pseudocapacitive Sodium Ion Storage

“…As shown in Figure 3g, the slope of log( v )–log( i ) provides a direct insight into the energy storage mechanism, that is, being equal to 0.5 indicates a total diffusion‐controlled process and 1.0 suggests a typical capacitive behavior. [ 35,36 ] The slope values of the 2D‐Co(OH) 2 @D NSs for anodic and cathodic processes are 0.78 and 0.74 respectively at scan rates ranging from 0.1 to 10 mV s −1 , indicating a crucial contribution from surface/near‐surface reactions. [ 37 ] Note that a similar CV behavior is also found in the 2D‐Co(OH) 2 NSs anode (anodic: 0.79, cathodic: 0.73, Figure S12b, Supporting Information).…”

Electronic and Structural Engineering of Atomically Dispersed Isolated Single‐Atom and Alloy Architectures

“…[ 194 ] Both nanostructure and atomic‐level synergistic involvement were witnessed in the interconnected 3D hierarchically porous structure with Nb single‐atom modulation within a Co 3 O 4 nanocage. [ 195 ] Stable single‐atom Pt with high‐density active sites with the formation of surface peroxo species on CeO 2 film is known to favor the dense and uniform distribution. [ 196 ] However, in many metal oxide‐based SACs, durability is a significant challenge in strongly acidic mediums.…”

Quantitatively Tunable Anionic Vacancies of Iron Disulfide Nanorods with Superior Cyclability and Rate Capability for Li-Ion Batteries

“…As the traditional energy cannot meet the increasing consumption demand, the energy storage device with high energy density is one of the research hotspots at present. − Lithium-ion batteries (LIBs) have been applied into a variety of portable electronic devices and smart grid on account of high energy and power density, no memory effect, low self-discharge, and environmental benignity. − However, in the last three decades of exploration, only low-capacity graphite anodes (372 mA h g –1 ) can be applied in LIBs. , Conversion-type anode materials with high theoretical capacity (500–1000 mA h g –1 ), such as transition metal oxides, phosphates, nitrides, carbides, sulfides (TMSs), have been attracted extensive attention. − Among the TMSs, iron disulfide (FeS 2 ) is supposed to be the most promising candidate for the anode material with natural abundance, low cost, eco-friendliness, and high theoretical capacity (894 mA h g –1 ) based on the formation of Li 2 S with the four-electron migration. , Nevertheless, the application of FeS 2 is also limited by the following aspects: (1) sluggish diffusion kinetics of Li + due to its semiconductor properties and (2) inferior cyclicality because of volume expansion during the discharge/charge process. , …”