Ethylene glycol-assisted nanocrystallization of LiFePO4 for a rechargeable lithium-ion battery cathode

Abstract

Hydro-and/or solvo-thermal nanocrystallization of lithium iron phosphate (LiFePO 4 ) has been well recognized as an effective pathway to improve its electrochemical performances. Herein, it is reported that high-performance LiFePO 4 single-crystalline nanoparticles have been successfully prepared by the additive-free solvothermal reaction and subsequent glucose-assisted calcination. In comparison with the similar hydrothermal reaction, the presence of ethylene glycol can unexpectedly induce the formation of gel-like intermediates at the time interval of 0.5 h, resulting in LiFePO 4 nanoparticles with a three-dimensional (3D) lattice structure and an amorphous nanocoating for a reaction time of 2 h. Interestingly, the lattice structure of growing LiFePO 4 crystals can be thoroughly damaged under the irradiation of an electron beam. Furthermore, after the continuous crystal growth and subsequent heattreatment, nanocrystalline LiFePO 4 can achieve a discharge capacity of $165 mAh g À1 at 0.1 C in assembled LiFePO 4 /Li half-cells, proving a successful nanocrystal-forming engineering of LiFePO 4 for a lithium-ion battery cathode.

Enhanced rate performance of multiwalled carbon nanotube encrusted olivine type composite cathode material using polyol technique

“…The bands around 504 and 470 cm À1 are observed to translation of lithium ions for olivine LiFePO 4 . These observed characteristics bands are good agreement with the earlier reports [34,39]. The band between 1550 and 1625 cm À1 is elucidating existence of stretching vibration of C]C bonding and hydroxide groups on the prepared both samples [40].…”

Improvement of electrochemical and electrical properties of LiFePO4 coated with citric acid

“…The particles of LF samples are fine-grained, because EG was added during the synthesis to reduce the solubility of the metal ions. The crystal growth might be inhibited by the presence of EG, and so smaller particles form [17,31]. The LF sample shows a particle size of about 0.5-1.0 lm.…”

Effect of ethylene glycol on morphology, crystallinity, and electrochemical properties of LiFePO4/C in lithium-ion batteries

“…It seems that, adding the EG in the electrolyte of the preparation of LiFePO 4 by hydrothermal method can improve the electrochemical performance. However, the optimized amount of EG in previous reports was not determined [22,[30][31][32][33][34][35][36][37]. Therefore, in this work, LiFePO 4 /C has been synthesized using hydrothermal method with various volume ratios of EG to water, and the effects of EG on the morphology, crystallinity, and electrochemical properties of LiFePO 4 were investigated.…”

“…Hence, it can inhibit the crystal growth so that smaller particles are obtained [30][31][32][33][34][35]. In addition, EG is able to reduce the intrinsic defect concentration of the products [34,36].…”