Review: Phase transition mechanism and supercritical hydrothermal synthesis of nano lithium iron phosphate

Comprehensive Understanding of Structure Transition in LiMnyFe1−yPO4 during Delithiation/Lithiation

“…When the rate beyond 0.2C, it transitioned to solid solution mechanism. [39] For LFP with a particle size of ≈190 nm, in situ XRD revealed the formation of a non-equilibrium solid solution phase at a high rate (10C). [28a] At an even higher rate (60C), LFP exhibited a nonequilibrium solid solution phase as the primary composition during the charge/discharge processes, indicating a solid solution mechanism.…”

The Progress and Future Prospects of Lithium Iron Phosphate Cathode Materials

“…According to the investigation in Ref. [11], the temperature and pressure rise to the critical value, the vapor pressure and the number of products rise, the fluid density, viscosity and surface tension decrease.…”

Effect of the Heating Rate to Prevent the Generation of Iron Oxides during the Hydrothermal Synthesis of LiFePO4

“…The global and increasing energy demand, and the need to replace the consequential consumption of fossil fuels because of environmental concerns, has generated a growing interest, not only in the development of renewable sources of energy, but also in the design of more advanced energy storage systems such as lithium-ion batteries (LIBs) [ 1 ], super capacitors [ 2 ], lithium sulfur batteries [ 3 ], sodium sulfur batteries [ 4 ], and redox flow batteries [ 5 ] with improved energy density and cycling performance. Nowadays, LIBs are important energy storage devices because of their high specific energy, low self-discharge, excellent cycle performance, no memory effect, and lesser environmental impact [ 6 ]. About 30% of the manufacturing budget for LIBs is spent on cathode materials, and its level of development is lower than that of the negative electrode, the diaphragm, or the electrolyte.…”

“…About 30% of the manufacturing budget for LIBs is spent on cathode materials, and its level of development is lower than that of the negative electrode, the diaphragm, or the electrolyte. Therefore, it is the “control step” that determines the battery performance in terms of working voltage, energy density, and rate performance [ 6 ]. Numerous cathodic materials have been employed, such as LiMn 2 O, Li 3 V 2 (PO 4 ) 3 , and LiCoO 2 , but it is LiFePO 4 that has become the main one used because of its excellent performance, as well as its high theoretical specific capacity (170 mA·h·g −1 ), practical operating voltage (3.5 V vs. Li + /Li), long life cycle, superior safety, low cost, low toxicity, abundant resources, and lesser environmental impact [ 7 ].…”

“…To date, many studies have focused on the production of LiFePO 4 particles by different methods such as: solid state synthesis [ 8 , 9 , 10 ], mechanochemical activation [ 10 , 11 ], sol−gel synthesis [ 10 , 12 ], coprecipitation [ 10 , 13 , 14 ], and hydrothermal synthesis [ 6 , 10 ], among others [ 7 ]. Among all of them, hydrothermal synthesis has been gaining prominence since its capacity to produce extremely pure and crystalline particles using relatively low temperatures (115–400 °C) [ 15 , 16 ] has been demonstrated, and in relatively short reaction times (from seconds to hours) [ 17 , 18 ].…”