Effect of Different Calcination Temperatures and Carbon Coating on the Characteristics of LiFePO4 Prepared by Hydrothermal Route

Abstract

Despite its many advantageous, however, LiFePO 4 also has a drawback in that its electronic conductivity is low, measured only 10 -9 S/cm [3]. This low electronic conductivity could lead to a low rate capability. Because of that, several approaches have been proposed by many investigators to improve this conductivity, e.g. refining the grain to nanoscale [4] Solid state route has attracted many investigators due to the ease of the process; however, solid state synthesis needs high temperature for sintering process in addition to the impurity problems dominated by Li 3 PO 4 and Fe 2 O 3 [21]. In the electrochemical reaction during charge-discharge process, the material containing these impurities will degrade and reduce the capacity of the active material [22]. The alternative is to synthesize LiFePO 4 by using hydrothermal route, which involves wet chemical process at low temperature followed by purifying process at relatively high temperature. This route has some advantages such as simple process and relatively low crystallization temperature and thus energy consumption [23]. In addition, the impurities could also be controlled during the reaction process [24].In this work, LiFePO 4 was prepared using the hydrothermal route. The characteristics of the material after calcination at various different temperatures are presented. Further, the effect of carbon coating on the LiFePO 4 performance in a lithium ion battery cathode is also examined and discussed.

High‐Conductivity–Dispersibility Graphene Made by Catalytic Exfoliation of Graphite for Lithium‐Ion Battery

“…A gain of weight starting at ≈360 °C is observed due to the oxidation of LiFePO 4 that forms Fe 2 O 3 and Li 3 Fe 2 (PO 4 ) 3 . [ 40 ] A weight loss starting at ≈600 °C is observed due to oxidation of graphene. The amount of HCDG in the composite is estimated to be ≈8.7 wt%.…”