ZnO-doped LiFePO4 cathode material for lithium-ion battery fabricated by hydrothermal method

Abstract

LiFePO4 particles doped with zinc oxide was synthesized via a hydrothermal route and used as cathode material for lithium-ion battery. Sample of preferable shape and structure was obtained by a concise and efficient process. ZnO doping into the LiFePO4 matrix was positively confirmed by the results of X-ray diffraction (XRD); high-resolution transmission electron microscopy (HRTEM); energy dispersive spectrometer (EDS), and X-ray photoelectron spectroscopy (XPS). LiFePO4 doped with ZnO tends to form nanometer-size and homogeneous particles, which can improve markedly the performance and stability of charge-discharge cycle. A specific discharge capacity of ZnO-doped LiFePO4 at 132.3 mAh g-1 was achieved, with 1.8% decrease after 100 cycles. Based on the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) results, it has further shown that ZnO doping effectively reduces the impacts of polarization and transfer resistance during electrochemical processes. Abstract:LiFePO 4 particles doped with zinc oxide was synthesized via a hydrothermal route and used as cathode material for lithium ion battery. Sample of preferable shape and structure was obtained by a concise and efficient process. ZnO doping into the LiFePO 4 matrix was positively confirmed by the results of X-ray diffraction (XRD); high-resolution transmission electron microscopy (HRTEM); energy dispersive spectrometer (EDS), and X-ray photoelectron spectroscopy (XPS).

Preparation of Micro–Nano-Structured FePO4·2H2O for LiFePO4 Cathode Materials by the Turbulent Flow Cycle Method

“…As can be seen, the polarization of the cathode material between the charge/discharge plateau becomes lower and remains unchanged after the first cycle. The stable charge and discharge plateaus can be observed at around 3.5 and 3.4 V, which is in agreement with the reported figures. − The charge capacity is 153.8 mAh·g –1 in the 2nd cycle and 152.3 mAh·g –1 in the 31st cycle, the corresponding discharge capacities are 153.6 and 151.5 mAh·g –1 , respectively. The result shows that 98.6% of the capacity is retained after 30 cycles.…”

Effect of Ru Doping on the Properties of LiFePO4/C Cathode Materials for Lithium-Ion Batteries

“…This may be attributed to the fact that Ru doping can promote the nucleation process and effectively inhibit the particle growth at high temperature. 34,35 The finer particle size and better dispersion can reduce the diffusion path of Li + and provide a larger surface for Li + extraction/insertion, resulting in its enhanced diffusion speed. The energy-dispersive In order to better understand the valence of Ru, LFP-1 was characterized by XPS, and the results are shown in Figure 8.…”

Solvothermal Synthesis of a Hollow Micro-Sphere LiFePO4/C Composite with a Porous Interior Structure as a Cathode Material for Lithium Ion Batteries

“…The sizes of the primary particles of LFP-A and the whole particles of LFP-B synthesized via our solvothermal route are smaller than that of the particles synthesized by the hydrothermal route in our previous work [21]. The size reduction of particles is attributed to the organic solvent EG which has two hydroxyl groups in its molecule, capable of weak linking to the LFP nanocrystallites via hydrogen bonds, thus inhibiting the growth of the crystals [15].…”

“…However LiFePO 4 suffers from two main disadvantages: low ionic-electronic conductivity (10 −9 –10 −10 S cm −1 ) and limited lithium ion diffusion channel (one-dimensional path along the b-axis), which significantly restricts the rate performance when attempting fast charging or discharging [4,5]. Tremendous efforts have been exerted to overcome the electronic and ionic transport restriction by optimizing morphology [6,7,8], reducing particle size [9,10,11,12,13], decorating the surface with electricallyconducting agents [14,15,16], and doping the host framework with supervalent cations [17,18,19,20,21]. Among these strategies, size reduction and carbon coating are considered as effective methods to improve the performance of LiFePO 4 , but there still remain some fundamental and technical challenges.…”