Synthesis of LiNi1/3Co1/3Al1/3O2 cathode material with eutectic molten salt LiOH-LiNO3

Abstract

A lithium-ion battery cathode material, LiNi 1/3 Co 1/3 Al 1/3 O 2 , with excellent electrochemical properties was prepared by three-phase temperature sintering, using eutectic lithium salts (0.38LiOH.H 2 O-0.62LiNO 3 ) mixed with the precursor Ni 1/3 Co 1/3 Al 1/3 (OH) 2 . This method was simple and inexpensive, and the materials could be mixed uniformly at the eutectic melting point without any grinding. A well-layered α-NaFeO 2 structure was confirmed by X-ray diffraction (XRD). The ratio of characteristic diffraction peaks I(003)/I (104) reached 1.73. Charge-discharge testing of the synthesized powder showed an initial chargedischarge capacity of 151.5 mAh.g -1 at a specific current of 0.2 C in the range 2.8-4.3 V up to 20 cycles with no noticeable capacity-fading (94.5% of the first discharge capacity), and reversible capacities of 133.7 and 120.9 mAh.g -1 for specific currents of 1 C and 2 C at room temperature. The discharge capacity and capacity retention at 55°C were substantially better than at room temperature.

Ambient‐Pressure Relithiation of Degraded LixNi0.5Co0.2Mn0.3O2 (0 < x < 1) via Eutectic Solutions for Direct Regeneration of Lithium‐Ion Battery Cathodes

“…The endothermic peak at 100 °C corresponds to the loss of absorbed water from LiNO 3 since it is hygroscopic, as revealed in the dramatic weight loss in the thermogravimetric analysis (TGA) curve (Figure b). A second endothermic peak at 176 °C corresponds to the melting of the eutectic molten salt . The exothermic peak at 250 °C (Figure a) and the corresponding weight loss in the temperature range of 250–350 °C can be ascribed to gas evolution.…”

“…Particularly, Li‐based eutectic molten salts have been used as both the Li source and the “solvent” to react with TM precursors for the synthesis of high‐performance LIB cathodes . Among different eutectic systems formed by common Li salts, the mixture of LiNO 3 and LiOH at a molar ratio of 3:2 is of great interest for us due to its lowest melting point at ≈175 °C . This type of unique eutectic Li solution system has great potential for relithiation of degraded cathode materials at ambient pressure and low temperature.…”

Prospect and Reality of Ni‐Rich Cathode for Commercialization

“…It is well known that the flux growth method provides highly developed oxide compounds at low temperature compared with the solid-state reactions. [149,[158][159][160][161][162][163] The mechanisms for the crystal growth at low temperature was closely associated with Ostwald ripening in molten salts. [164][165][166][167] The molten salts of the chemical reagents could lower the melting temperature of the cathode precursor, and the cathode continuously dissolved and reprecipitated at the surface, resulting in the synthesis of narrow sized single crystalline cathode.…”

“…The representative synthetic method was the flux growth method. It is well known that the flux growth method provides highly developed oxide compounds at low temperature compared with the solid‐state reactions . The mechanisms for the crystal growth at low temperature was closely associated with Ostwald ripening in molten salts .…”

Two‐step solvothermal synthesis of high capacity LiNi0.8Co0.15Al0.05O2 cathode for Li‐ion batteries

“…There are numerous methods for synthesis LiNi x Co y Al 1‐x‐y O 2 have been reported, [ 25,26 ] including hydrothermal method, [ 27,28 ] sol–gel method, [ 29,30 ] solid‐phase calcined method, [ 31 ] spray drying method, [ 32 ] electrospinning, [ 33 ] and molten salt method. [ 34 ] Jae‐Sung Seo et al [ 35 ] synthesized (Ni 0.8 Co 0.16 Al 0.04 )(CO 3 ) 0.41 (OH) 1.18 and (Ni 0.8 Co 0.16 Al 0.04 )(OH) 2 precursor using different precipitation agents. Compared with hydroxide precipitation, the reaction time of carbonate precipitation is significantly reduced and the precipitation conditions are more stable.…”