Highly Stable Cycling of Amorphous Li₂CO₃-Coated α-Fe₂O₃Nanocrystallines Prepared via a New Mechanochemical Strategy for Li-Ion Batteries

Abstract

In this study, an amorphous Li2CO3‐coated nanocrystalline α‐Fe2O3 hierarchical structure is synthesized for the first time using a facile one‐step mechanochemical process at room temperature, taking advantage of the concurrence of repeated fracture‐cold welding of material's particles and a gas‐solid redox reaction. The conformal coating and hierarchical structure significantly increase the cycling durability and rate capability. Typically, a 1–3 nm thick amorphous Li2CO3 layer is conformally coated on Fe2O3 nanocrystallines (≈10 nm in size) that form hierarchically aggregated particles 400–800 nm in size by ball milling α‐Fe2O3 with LiH in CO2. The prepared Li2CO3‐coated nanocrystalline α‐Fe2O3 exhibits highly stable long‐term cyclability as it delivers a reversible capacity of 975 mAh g−1 with 99% of retention after 400 cycles at 100 mA g−1. At a high rate of 3000 mA g−1, its reversible capacity still remains at 537 mAh g−1, superior to the uncoated counterpart (311 mAh g−1). Moreover, amorphous Li2O and Li2CO3 coatings are also similarly produced on Fe2O3 and NiO nanocrystallines, respectively, representing the general applicability of this mechanochemical approach.

Electrolytes Polymerization‐Induced Cathode‐Electrolyte‐Interphase for High Voltage Lithium‐Ion Batteries

“…[33] The difference of carbon species was also confirmed by the ATR-FTIR results of cycled cathode laminates (Figure S10, Supporting Information), which showed additional CO bands at 1425 and 1500 cm -1 assigned to Li 2 CO 3 after 200 cycles. [34] Apart from polycarbonate, Al 2 O 3 and AlF 3 were also observed in the Al 2s spectrum of 1% AIP modified cathode (Figure 4b), while no obvious signal was detected from bare cycled NCM (Figure 4d). Both Al 2 O 3 and AlF 3 are widely adopted in the cathode material coating, which could increase the structural stability and depress irreversible phase change.…”

Optimization of Von Mises Stress Distribution in Mesoporous α‐Fe2O3/C Hollow Bowls Synergistically Boosts Gravimetric/Volumetric Capacity and High‐Rate Stability in Alkali‐Ion Batteries

“…The initial Coulombic efficiency is 78% and quickly increases to 94.2% in the second cycle. This phenomenon, in which the capacity exceeds the theoretical value implies the presence of a hybrid lithium‐storage mechanism, consisting of the abovementioned redox conversion and surface capacitive behavior including non‐Faradaic electrical double layer capacitance and pseudocapacitance . To evaluate the capacity contributions of the two mechanisms, CV profiles were recorded at different scan rates from 0.1 to 1.1 mV s −1 (Figure f).…”

Cluster‐Bridging‐Coordinated Bimetallic Metal−Organic Framework as High‐Performance Anode Material for Lithium‐Ion Storage

“…[ 5,6 ] Extensive efforts have been dedicated to developing desirable anode materials with high capacity, rate capability, and cycling stability. Transition metal oxides/sulfides/nitrides, [ 7–10 ] Si‐based composites, [ 11–14 ] and carbonaceous materials [ 15–18 ] have attracted considerable interest as potential anode materials due to their high capacity. However, the large volume variation that occurs during the lithiation/delithiation processes renders the solid‐electrolyte interphase (SEI) unstable and leads to pulverization of the electrode, which could result in fast capacity degradation of the battery.…”