Low-Temperature Synthesis of LiFePO₄ Nanoplates/C Composite for Lithium Ion Batteries

Abstract

The LiFePO4 nanoplates/C composite was synthesized by a low-temperature precipitation approach around 106 °C. X-ray powder diffraction refinement revealed a smaller crystallographic cell volume of this composite compared to stoichiometric LiFePO4, implying the presence of Li vacancies. Moreover, Mössbauer analysis evidenced Fe3+ with content as large as 26 at. %, which was related to amorphous ferric phase (LiFePO4(OH)) in the composite. A short low-temperature annealing under reducing condition can convert this amorphous phase to crystalline LiFePO4. This achieves significant improvement in the electrochemical performance of the LiFePO4/C composite with reversible discharge capacity of 142 mAh g–1 at C/20 and 82 mAh g–1 at 2 C, which are much higher than 105 and 49 mAh g–1 of the bare LiFePO4 at the same current rates, respectively.

Review on Defects and Modification Methods of LiFePO4 Cathode Material for Lithium-Ion Batteries

“…As a result of the advantages of an extended cycle life, high specific capacity, and no pollution, LFP is widely used in various fields. However, lithium-ion batteries in low-temperature environments generally suffer from serious capacity decay, poor multiplicative performance, and lithium dendrite phenomenon during use, and the discharge capacity at −20 °C can only reach 67.38% of the room-temperature capacity. − Problems such as capacity decay and reduced electrochemical performance at lower temperatures have limited the application of lithium-ion batteries in aerospace, military, and electric vehicle applications, where temperature conditions are harsh.…”

Virtual Special Issue of Research Highlights on Sustainable Energy and Clean Fuels at State Key Laboratory of Materials-Oriented Chemical Engineering (SKL-MCE), China

“…The NiCo 2 O 4 NWs/CPs composite electrode exhibits outstanding capacity and ideal cycling performance as a result of the unique architecture, which enhances electrical conductivity and accommodates NiCo 2 O 4 expansion during lithiation. Sun et al investigate the synthesis of LiFePO 4 nanoplates/C composite by a low-temperature precipitation approach around 106 °C for LIBs. A short low-temperature annealing under reducing conditions converts the amorphous LiFePO 4 (OH) phase to crystalline LiFePO 4 , leading to a significant improvement in the electrochemical performance of the LiFePO 4 /C composite compared to bare LiFePO 4 .…”

Novel Synthesis of 3D Mesoporous FePO4 from Electroflocculation of Iron Filings as a Precursor of High-Performance LiFePO4/C Cathode for Lithium-Ion Batteries

“… 11 , 12 It is evident that the nanostructure facilitates shorter ion diffusion paths, resulting in high efficiency. 13 , 14 Various methods have been developed to prepare nanostructure LFP particles to facilitate Li + diffusion, including hydrothermal/solvothermal, 15 , 16 sol–gel, 17 and hard-templating approaches. 18 − 20 Surface conductive coating and ion doping are complementally used to enhance the migration of electrons.…”

“…Lithium-ion diffusion in LFP is preferably one-dimensional along the b -axis. , It is evident that the nanostructure facilitates shorter ion diffusion paths, resulting in high efficiency. , Various methods have been developed to prepare nanostructure LFP particles to facilitate Li + diffusion, including hydrothermal/solvothermal, , sol–gel, and hard-templating approaches. − Surface conductive coating and ion doping are complementally used to enhance the migration of electrons. − However, the high-performance nanostructured LFP suffers from low tap density and volumetric energy density limitations . With these drawbacks, extensive studies have been initiated to explore novel LFP nanostructures.…”