Nanocrystal Conversion Chemistry within Slit-like 2D Nanogap for High-Rate Cyclic Stability of Lithium-Ion Battery Anodes

Abstract

Nanoscale optimization of late transition-metal oxides for fixing the reversible lithiation/delithiation mechanism with an in-depth mechanistic understanding of nanocrystal (NC) conversion chemistry is important for furthering next-generation Li-ion battery (LIB) technologies. Herein, 1 nm-thin Ni3CoO x (1 nm-NCO) nanosheets synthesized through isomorphic transformation of NiCo layered double hydroxides within a two-dimensional (2D)-SiO2 envelope are chosen. The interconversion of metal/metal-oxide NCs under redox-switching thermal treatment, while retaining reversibility, inspired the accomplishment of identical consequences under the harsh operational conditions of LIB redox cycles by application of the thin-NCO-defined 2D nanospace. During charge/discharge cycles, 1 nm-NCO covered with an in situ formed solid-electrolyte-interphase layer enables fully reversible interconversion between the reactive NC redox pairs, as evidenced by detailed morphological and electrochemical analyses, thus providing high-rate capability with a specific capacity of 61.2% at 5.0 C relative to 0.2 C, outstanding cycle stability delivering a reversible capacity of 1169 mAh g–1, and 913 mAh g–1 with high average Coulombic efficiency (>99.2%) at 3.0 and 5.0 C for 1000 cycles, respectively, which has not been achieved with other transition-metal oxides. Such a nanospace-confinement effect on sustainability of reactive NCs to follow-up a highly reversible conversion reaction at fast charging in LIBs is operative within a slit-like ultrathin 2D nanogap from 1 nm-NCO only, as a relatively thicker 7 nm-NCO anode, with accompanying larger space available, has evidenced poor reversibility of NCs and inadequate cyclic stability under potential high-power density LIB application.

Ultrathin silica-tiling on living cells for chemobiotic catalysis

“…1 , Fig. 2a, b ) 42 . 2D-SiNT has a silica bilayer morphology with customizable interior nanospace (~1 nm) where different catalytic metals can be selectively functionalized.…”

Unlocking Catalytic Potential: Encasing CoP Nanoparticles within Mesoporous CoFeP Nanocubes for Enhanced Oxygen Evolution Reaction

“…However, CoP/CoFeP well retains the encased structure of the ZIF-67/CoFe PBA, strongly indicating that the CoFeP shell effectively prevents the aggregation of CoP NPs (Figure S7a,b). − Hollow CoFe PBA is also converted to hollow CoFeP without any collapse (Figure S7c,d). Some mesopores are present on the surface of CoP/CoFeP and hollow CoFeP (Figure a,b,f,g).…”

A Layered Bi2Te3@PPy Cathode for Aqueous Zinc‐Ion Batteries: Mechanism and Application in Printed Flexible Batteries

“…CV measurements at various scan rates (0.1-0.6 mV s −1 , 0.2-1.6 V) were used to distinguish the contribution of different storage mechanisms. A power-law relationship between peak current (i) and scan rate (v) was considered to fit the data: [43] i = av b…”