Excellent temperature performance of spherical LiFePO4/C composites modified with composite carbon and metal oxides

ScientificWorldJournal. 2014 Jan 9:2014:364327. doi: 10.1155/2014/364327. eCollection 2014.

Abstract

Nanosized spherical LiFePO4/C composite was synthesized from nanosized spherical FePO4 ·2H2O, Li2C2O4, aluminum oxide, titanium oxide, oxalic acid, and sucrose by binary sintering process. The phases and morphologies of LiFePO4/C were characterized using SEM, TEM, CV, EIS, EDS, and EDX as well as charging and discharging measurements. The results showed that the as-prepared LiFePO4/C composite with good conductive webs from nanosized spherical FePO4 ·2H2O exhibits excellent electrochemical performances, delivering an initial discharge capacity of 161.7 mAh·g(-1) at a 0.1 C rate, 152.4 mAh·g(-1) at a 1 C rate and 131.7 mAh·g(-1) at a 5 C rate, and the capacity retention of 99.1%, 98.7%, and 95.8%, respectively, after 50 cycles. Meanwhile, the high and low temperature performance is excellent for 18650 battery, maintaining capacity retention of 101.7%, 95.0%, 88.3%, and 79.3% at 55°C, 0°C, -10°C, and -20°C by comparison withthat of room temperature (25°C) at the 0.5 C rate over a voltage range of 2.2 V to 3.6 V, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon / chemistry*
  • Electrochemistry
  • Iron / chemistry*
  • Lithium / chemistry*
  • Nanostructures / chemistry
  • Oxides / chemistry*
  • Phosphates / chemistry*
  • Temperature
  • Thermodynamics

Substances

  • LiFePO4
  • Oxides
  • Phosphates
  • Carbon
  • Lithium
  • Iron