Highly-dispersed Li
3V
1.8Al
0.2(PO
4)
3 nanoparticles which are directly impregnated onto the surface of multi-walled carbon nanotubes (MWCNT) were successfully synthesized via a unique two-step process using an ultracentrifugation at 75,000 g. The synthetic procedure of the Li
3V
1.8Al
0.2(PO
4)
3/MWCNT composite involves the following two steps: i) precipitation of V
1.8Al
0.2O
3 (10–100 nm) nanoparticles on the surface of MWCNT, and ii) the subsequent transformation of the V
1.8Al
0.2O
3 into the Li
3V
1.8Al
0.2(PO
4)
3 nanoparticles without any change of their shape and dimensions. The 10% of Al-doping brought out an increase in the discharge capacity from 119 to 124 mAh g
−1 per Li
3V
2−xAl
x(PO
4)
3, which corresponds to a 14% increase of the Li
3V
2−xAl
x(PO
4)
3 utilization ratio. The Al-doping also reduced its electric resistance by 26%. The Li
3V
1.8Al
0.2(PO
4)
3/MWCNT with such an efficient electron transport can deliver excellent electrochemical performances ever attained to date; capacity density of 85 mA h g
−1 at a high discharge rate of 480C and stable cycle performance over 10,000 cycles at 10C rate with 85% retention of the initial capacity.
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