Surface modification of Li-rich layered Li(Li0.17Ni0.25Mn0.58)O2 oxide with Li–Mn–PO4 as the cathode for lithium-ion batteries

Abstract

Enhancement of the discharge capacity, high-rate capability, and cycle stability of the Li-rich layered Li(Li 0.17 Ni 0.25 Mn 0.58 )O 2 oxide with a large specific capacity is highly significant for high energy lithiumion batteries. In this work, the Li-rich layered Li(Li 0.17 Ni 0.25 Mn 0.58 )O 2 oxide is prepared by a spray-drying method. The surface modification with the Li-Mn-PO 4 is introduced onto Li-rich layered Li(Li 0.17 Ni 0.25 Mn 0.58 )O 2 oxide for the first time. It is demonstrated that the surface of Li(Li 0.17 Ni 0.25 Mn 0.58 ) O 2 grains is coated with the thin amorphous Li-Mn-PO 4 layer (5 wt%). With increasing calcination temperature after the surface coating, a strong interaction can be induced on the interface between the amorphous Li-Mn-PO 4 layer and the top surface of Li(Li 0.17 Ni 0.25 Mn 0.58 )O 2 grains. As anticipated, the discharge capacity and high-rate capability are obviously improved for the Li-Mn-PO 4 -coated sample after calcination at 400 C, while excellent cycle stability is obtained for the Li-Mn-PO 4 -coated sample after calcination at 500 C as compared with the as-prepared Li(Li 0.17 Ni 0.25 Mn 0.58 )O 2 oxide during cycling. Apparently, the interface interaction between the amorphous Li-Mn-PO 4 layer and the top surface of Li(Li 0.17 Ni 0.25 Mn 0.58 )O 2 grains is responsible for the improvement of the reaction kinetics and the electrochemical cycle stability of Li-Mn-PO 4 -coated samples.

Toward Low-Cost, High-Energy Density, and High-Power Density Lithium-Ion Batteries

“…The phase change also results in a somewhat more complex CEI formation mechanism than that of Ni-rich NMC. 130,131 Strategies to stabilize the surface of Li-rich NMCs include coatings, [132][133][134][135] surface treatments, 126 cycling protocols, 136 synthesis routes, 137,138 and electrolyte additives. 135 Most of these efforts have failed to stop the underlying mechanisms responsible for voltage fade, 135 although compositions that incorporate small amounts of spinel domains into the layered structure show some promise.…”

Surface Modification of Over-Lithiated Layered Oxides with PEDOT:PSS Conducting Polymer in Lithium-Ion Batteries

“…The inorganic materials, which include AlF 3 , AlPO 4 4 , and Li-Ni-PO 4 , are known to decrease the irreversible capacity and improve the electrochemical performances of OLO materials owing to the enforcement of stability on the surface in the high-voltage region. [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] The carbon materials, including graphene-based materials, are employed to improve the electronic conductivity of OLO cathode materials. 19,[32][33][34] Also, surface modification by conducting polymers, such as polypyrrole, has been recently reported to provide improved electronic conductivity as well as a thin protective layer on OLO cathode materials.…”

La2O3-coated Li1.2Mn0.54Ni0.13Co0.13O2 as cathode materials with enhanced specific capacity and cycling stability for lithium-ion batteries

“…It has been proved that the coating layer could protect the active materials against the attack of hydrofluoric acid by separating them from electrolyte, suppress the oxygen loss by reducing the activity of oxygen ions, and retain the oxygen-ion 4 vacancies [31,32]. Many compounds have been explored as the coating layer, such as metallic phosphates [34,35], oxides [36][37][38] and fluorides [39][40][41]. products were sintered at 500 o C for 5 h in air to get LMNC-L powders.…”