Structural and Morphological Tuning of LiCoPO4 Materials Synthesized by Solvo-Thermal Methods for Li-Cell Applications

Abstract

, in order to obtain higher redox potentials. In this communication we report a systematic analysis of the synthesis condition of LiCoPO4 (LCP) using a solvo-thermal route at low temperature, the latter being a valuable candidate to overcome the theoretical performances of LFP. In fact, LCP shows higher working potential (4.8 V vs. 3.6 V) compared to LFP and similar theoretical capacity (167 mAh·g −1 ). Our goal is to show the effect of the synthesis condition of the ability of LCP to reversibly cycle lithium in electrochemical cells. LCP samples have been prepared through a solvo-thermal method in aqueous-non aqueous solvent blends. Different Co 2+ salts have been used to study the effect of the anion on the crystal growth as well as the effect of solution acidity, temperature and reaction time. Materials properties have been characterized by Fast-Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopies. The correlation between structure/morphology and electrochemical performances has been investigated by galvanostatic charge-discharge cycles.

Solvothermal water-diethylene glycol synthesis of LiCoPO4and effects of surface treatments on lithium battery performance

“…62 Mixing an organic solvent and water as a co-solvent has been employed in the solvothermal synthesis of LiCoPO 4 . 44,45,[62][63][64] The solvent mixture can be benecial for effectively tailoring the particle size of LiCoPO 4 due to the high viscosity of the organic solvent, 62,63 and the water component can promote the dissolution of the reagents. 62 However, optimisation of solvothermal conditions to achieve LiCoPO 4 cathodes with good specic capacity and cycle performance is still challenging.…”

Enhanced Cycling Performance of Magnesium‐Doped Lithium Cobalt Phosphate

“…All samples are single‐phase without any additional peaks except LiMg 0.2 Co 0.8 PO 4 , which contains some diffraction peaks from an impurity phase, assigned to Li 3 PO 4 (ICSD database no.77095). It has been reported that the formation of impurities depends on the concentration and pH of reagents in hydrothermal and solvothermal synthetic methods . In this study, additional MgSO 4 may influence the pH of reaction medium, resulting in the formation of impurity phase Li 3 PO 4 .…”

“…It has been reported that the formation of impurities depends on the concentration and pH of reagents in hydrothermal and solvothermal synthetic methods. [47,48] In this study, additional MgSO 4 may influence the pH of reaction medium, resulting in the formation of impurity phase Li 3 PO 4 .…”

“…Samples were synthesised by a solvothermal method previously reported by Brutti and co‐workers with slight modification . Two aqueous solutions: solution A with lithium hydroxide monohydrate (LiOH⋅H 2 O, Sigma‐Aldrich, ≥98 %) and solution B containing lithium dihydrogen phosphate (LiH 2 PO 4 , Alfa Aesar, 97 %), cobalt sulphate heptahydrate (CoSO 4 ⋅7H 2 O, Sigma‐Aldrich, ≥99 %), and D‐(+)‐glucose (Sigma‐Aldrich) were prepared separately.…”

“…Synthesis of LiMg x Co 1-x PO 4 ( x = 0, 0.05, 0.10, 0.15 and 0.20) Samples were synthesised by a solvothermal method previously reported by Brutti and co-workers with slight modification. [7,47]…”