Roles of coating carbon, conductive additive and binders in lithium vanadium phosphate/reduced graphene oxide composite cathodes

Abstract

Supreme high rate cycling performance can be achieved by optimizing the composition of LVP electrode.

Investigating the Structure of an Active Material–Carbon Interface in the Monoclinic Li3V2(PO4)3/C Composite Cathode

“…Likewise, the LVP/Glu composite was synthesized using glucose (Jizhun Reagent, >99.0%), V 2 O 5 , NH 4 H 2 PO 4 , and Li 2 CO 3 in a stoichiometric ratio (2:1:3:1.75). LVP/GO, LVP/G, and LVP/SP composites were prepared using oxalic acid as chelating and reducing agent, and the quantity of elemental carbon source (GO, graphene, super P) was controlled at a mass ratio of 8 wt % (0.16 g) for optimized electrochemical performance . GO, graphene (Ningbo Moxi Technology Co., >99.9%), or super P (Lizhiyuan Co., >99.9%) was added during stirring at 80 °C.…”

“…Lithium-ion batteries (LIBs) are currently the most important energy storage devices for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and electric vehicles (EVs). , Among all cathode materials for LIBs, monoclinic lithium vanadium phosphate, Li 3 V 2 (PO 4 ) 3 (LVP), has gained intense attention because of high charge–discharge voltage, relatively high theoretical specific capacity, and thermodynamically stable structure. − Similar to other lithium transition metal phosphates, the electrochemical performance of LVP has been limited by its poor electronic conductivity due to the framework formed by VO 6 octahedra corner-sharing with PO 4 tetrahedra . Carbon coating is an economic and convenient method to enhance the electronic conductivity of electrode materials, which can also alleviate the aggregation of LVP particles during calcination. − It is usually achieved by introducing carbon sources, such as graphene, graphene oxide (GO), ,, carbon black, carbon nanoflakes, citric acid, − glucose, and humic acid, as raw materials.…”

Surface and Interface Modification of Electrode Materials for Lithium-Ion Batteries With Organic Liquid Electrolyte

“…And the activated porous carbon coated LFP (LFP/AC-P4) presents the increased Li-ions diffusion coefficient and low charge transfer resistance (Tian et al, 2020). Hence, it is disclosed that carbon coating is an important method to fabricate composites, which is able to be achieved by introducing a carbon source, such as graphene oxide (GO) (Huo et al, 2017), glucose (Zhang et al, 2017;Wang M. et al, 2019;He et al, 2020), sucrose (Chen et al, 2019;Park et al, 2019), pitch (Hsieh and Liu, 2020), cotton (Deng et al, 2019), ethylene glycol (Lin et al, 2008), and methyl orange (Yan et al, 2019), as raw materials. Besides, in the field of all-solid-state batteries, except the reconstruction of composite electrode materials, the controllable adjustment to composite solid electrolytes can effectively optimize the electrolyte interface.…”

Unraveling the Relationship between Ti4+ Doping and Li+ Mobility Enhancement in Ti4+ Doped Li3V2(PO4)3

“…Nowadays LiFePO 4 has been widely applied in the electric automobile for its low price and excellent cycling durability and safety. Li 3 V 2 (PO 4 ) 3 has been put forward as a cathode material with better prospect for higher operating voltage, higher energy density, and better low-temperature performances , compared with LiFePO 4 . The monoclinic LVP belongs to the P 2 1 / n space group with the three-dimensional network formed by apex sharing VO 6 octahedron and PO 4 tetrahedron.…”

“…For the purpose of enhancing the rate performance of LVP, Li-ion diffusivity and electron conductivity are the two most important influence factors that should be improved . Therefore, carbon coating ,− and ion doping , are employed to optimize the electrochemical performance of LVP. Carbon coating is a routine method to promote the electrochemical properties by enhancing the electron conductivity and inhibit particle aggregation .…”