In Situ K Doped γ-LiV₂O₅ as Long-Life Anode and Cathode for Lithium Ion Battery

Abstract

Based on the reaction process (γ′-is potential anode and cathode in a lithium ion battery. However, its poor structural stability during lithiation/delithiation results in unsatisfactory cyclic life. This work reports a low-temperature molten salt method to prepare in situ K doped γ-LiV 2 O 5 . With the as-prepared electrode acting as both anode (233 mAh g −1 after 2400 cycles at 1 A g −1 ) and cathode (128 mAh g −1 after 888 cycles at 0.2 A g −1 ), experimental results reveal that the K + doping distinctly improves structural reversibility, demonstrating the superior electrochemical properties of γ-LiV 2 O 5 for becoming an outstanding candidate in lithium ion batteries. KEYWORDS: γ-LiV 2 O 5 , in situ K + doping, anode and cathode, low-temperature molten salt method, long cyclic life

Construction of a LiVO3/C core–shell structure for high-rate lithium storage

“…22,39 The characteristic peaks at around 600 eV and 1000 eV were ascribed to the stretching vibrations of V-O bonds in low-valence lithium vanadate (LiV 2 O 5 ) in the Raman spectrum. 40 This phenomenon was most likely caused by a reduction of a very small amount of LiVO 3 by oxalic acid. Fitted higher Raman-shift spectra of the LiVO 3 /C hybrid are provided in Fig.…”

Low-Dimensional Vanadium-Based High-Voltage Cathode Materials for Promising Rechargeable Alkali-Ion Batteries

“…5.1%) [19], also superior to Na 1.5 VPO 4.8 F 0.7 synthesized by Kang and coworkers in 2013 (once the smallest volume change record, 2.9%) [59]. Some vanadium-based materials, mainly vanadium oxides [60] and vanadium oxide bronzes (VOBs), such as VO2 (e.g., nanowires) [10], layered V2O5 [61][62][63], γ-LiV2O5 [11], Some vanadium-based materials, mainly vanadium oxides [60] and vanadium oxide bronzes (VOBs), such as VO 2 (e.g., nanowires) [10], layered V 2 O 5 [61][62][63], γ-LiV 2 O 5 [11], monoclinic LiV 3 O 8 and doped Li 1+x V 3 O 8 (0 ≤ x ≤ 0.2) [64], usually have extraordinarily high capacities (some may be up to over 400 mA h g −1 for LIBs or close to 330 mA h g −1 for SIBs), although the voltage output is relatively low, e.g., with average voltage output (or long plateau of voltage) near or lower than 3.0 V, which are not focused on here and are cataloged into low-voltage cathode materials. And some similar VOBs (e.g., ω-Li 3 V 2 O 5 ), however, due to the phase transition (e.g.,…”

“…Vanadium-based materials are generally layered or tunnel-type materials and thus are typically intercalation hosts for alkali ions, characterized by their intercalation-deintercalation (or insertion-extraction) mechanism and electrochemically long plateaus as cathode materials for alkali-ion batteries [10,11]. In operando X-ray diffraction (also called in situ XRD) is an effective way to analyze the underlying crystal structure during cell cycling [12,13], thus facilely relating the electrochemical processes with crystal structure and phase transformation for revealing the (de)intercalation mechanisms, degradation mechanisms, and optimizing the performances [14,15].…”

“…on the reaction process), may be classified as anode materials due to the different alkali ion storage mechanisms and much lower plateaus (wholly or partly falling into the 0-2 V potential window), viz., these materials (V 2 O 5 -based) are binary materials that can both serve as cathodes and anodes [11]. For VOBs, the capacity of these cathode materials usually with mixed valence states may extend up to 200 mA h g −1 and beyond, although these materials usually demonstrate relatively low voltage output of ~2 V (an average discharge voltage vs. Li/Li + [32], Mg/Mg 2+ [65]) compared to high-voltage vanadium-based cathodes of >3.5 V; most of their electrochemical performances, especially the potential output plateaus, are somewhat similar to those of layered vanadium oxides (e.g., α-V 2 O 5 ), while some specific phases after transition or their corresponding VOBs could show elevated voltage outputs [66].…”