10.1016/j.electacta.2015.10.036
Li3V2(PO4)3/graphene nanocomposites with superior cycling performance as cathode materials for lithium ion batteries
In a typical synthesis, graphene oxide (GO) was prepared from natural graphite powder via a modified Hummers method [26] and [27]. 
Pure LVP was synthesized by using a sol-gel method reported in our previous paper [28]. First, oxalic acid (3.02 g) and V2O5 (1.46 g) in a stoichiometric ratio were dissolved in deionized water with magnetic stirring at 70 degC. After a clear blue solution formed, a mixture of stoichiometric NH4H2PO4 (1.84 g) and CH3COOLi*H2O (1.68 g) was added to the solution whilst stirring for 4 h, and then a gel formed in an air oven at 100 degC. The gel was decomposed at 350 degC in an argon atmosphere for 4 h, and the obtained product was ground, pressed into pellets, and sintered at 750 degC for 4 h in flowing argon. The sample was divided into two parts: one was further heated at 750 degC for 2 h in an argon atmosphere; the other was used to prepare LVP/G nanocomposites via a simple precipitation procedure, as described in detail as follows. The as-prepared LVP (1.0 g) was transferred to a suspension of 50 mg graphene oxide dissolved in 500 mL deionized water. The mixture was stirred for 12 h at room temperature after ultrasonic treatment for 2 h. Subsequently, the mixture was dried by freeze drying. Finally the dried sample was also sintered at 750 degC for 2 h in flowing argon.
oxalic acid
dissolved
3.02 g
g
V2O5
dissolved
1.46 g
g
mixture of stoichiometric NH4H2PO4 (1.84 g) and CH3COOLi*H2O (1.68 g) was added to the solution
stirring
4 h
h
mixture
NH4H2PO4
1.84 g
g
mixture
CH3COOLi*H2O
1.68 g
g
oxalic acid (3.02 g) and V2O5 (1.46 g) in a stoichiometric ratio were dissolved in deionized water
magnetic stirring
70 degC
degC
gel
formed
100 degC
degC
gel
decomposed
350 degC
degC
gel
decomposed
4 h
h
obtained product
sintered
750 degC
degC
obtained product
sintered
4 h
h
one
heated
750 degC
degC
one
heated
2 h
h
as-prepared LVP
ransferred
1.0 g
g
deionized water
500 mL
mL
graphene oxide
dissolved
50 mg
mg
mixture
stirred
12 h
h
mixture
ultrasonic treatment
2 h
h
dried sample
sintered
750 degC
degC
dried sample
sintered
2 h
h