FeF₃@Thin Nickel Ammine Nitrate Matrix: Smart Configurations and Applications as Superior Cathodes for Li-Ion Batteries

Abstract

Iron fluorides (FeF x ) for Li-ion battery cathodes are still in the stage of intensive research due to their low delivery capacity and limited lifetime. One critical reason for cathode degradation is the severe aggregation of FeF x nanocrystals upon long-term cycling. To maximize the capacity and cyclability of these cathodes, we propose herein a novel and applicable method using a thin-layered nickel ammine nitrate (NAN) matrix as a feasible encapsulation material to disperse the FeF 3 nanoparticles. Such core−shell hybrids with smart configurations are constructed via a green, scalable, in situ encapsulation approach. The outer thin-film NAN matrix with prominent electrochemical stability can keep the FeF 3 nanoactives encapsulated throughout the cyclic testing, protecting them from adverse aggregation into bulk crystals and thus leading to drastic improvements of electrode behaviors (e.g., high electrode capacity up to ∼423 mA h g −1 , greatly prolonged cyclic period, and promoted rate capabilities). This present work may set up a new and general platform to develop intriguing core−shell hybrid cathodes for Li-ion batteries, not only for FeF x but also for a wide spectrum of other cathode materials.

Graphitic, Porous, and Multiheteroatom Codoped Carbon Microtubes Made from Hair Waste: A Superb and Sustained Anode Substitute for Li-Ion Batteries

“…The S 2p spectrum (Figure I) shows two peaks at ∼163.8 and ∼165.0 eV, highly in agreement with the spin orbit coupling and the −C-S- covalent thiophene-S bond, respectively . The O 1s spectrum involves two distinct peaks located at ∼531.9 and ∼533.2 eV (Figure J), both of which are indexed to chemical groups in the form of carbonyl or carboxyl . Such heteroatoms doping properties may enrich the active places for redox reactions and thus enhance the delivered capacity for LIB applications.…”

“…20 The O 1s spectrum involves two distinct peaks located at ∼531.9 and ∼533.2 eV (Figure 2J), both of which are indexed to chemical groups in the form of carbonyl or carboxyl. 21 Such heteroatoms doping properties may enrich the active places for redox reactions and thus enhance the delivered capacity for LIB applications. For comparison study, we also characterize the CMTs (directly evolved from hairs by calcination at 650 °C in Ar) by XRD and Raman spectroscopy (see Figure S2 in the Supporting Information).…”

Hierarchical flower-like NiFe2O4 with core–shell structure for excellent toluene detection

“…XRD was conducted to identify the crystalline phases of the products, as shown in Fig. 2 [27,28]. This again illustrates that the tremendous influence of NH 4 F and urea in the formation of NiFe 2 O 4 .…”

Electrochemical Sensor Based on AgNPs‐NNH Nanocomposites for Hydrogen Peroxide Detection by Zero Current Potentiometry

“…Ni 3 (NO 3 ) 2 (OH) 4 (NNH) was synthesized firstly. [15] 0.45 g of C 6 H 12 N 4 and 0.2 g of Ni(NO 3 ) 2 ·6H 2 O were scattered in 40.0 mL of distilled water with intense agitation. Then the mixture was transferred into a Teflon-lined autoclave of 50.0 mL and held at 95 °C for 6 h. After cooling down to room temperature, the products were centrifuged, washed and dried.…”

“…Recently, the thin nickel nitrate hydroxide (NNH) has been confirmed as a novel and effective semiconducting material. [15] NNH is one type of thin layered α-Ni(OH) 2 with uniform thickness. Besides, NNH can be as supports for other materials because of its large specific surface area.…”