Ni/Fe mixed oxide and natural clay composite as anode material for Li-ion batteries

AUGUSTO RODRIGUEZ; MARIELA GISELA ORTIZ; J. E. THOMAS; ARNALDO VISINTIN

Mar del Plata

Congreso; 34th Topical Meeting International Society of of the Electrochemistry; 2023

INTEMA- Universidad Nacional de Mar del Plata

Thefast and continuous development of portable electronic devices, such as laptopsand cell phones, keeps increasing the demand for a new generation of high-energyand high-capacity materials for electrodes of lithium-ion batteries. Whilegreat efforts have been dedicated towards the development of new cathodematerials with high capacity, it is also required to continue, alongside, thedevelopment of novel anode materials. Transition metal oxides such as NiO andFe2O3 represent promising candidates for this purpose dueto their high discharge capacities; however, some deficiencies must still beovercome in order to reach their industrial and commercial scale application,such as a high level of volumetric expansion that limits the electrode cyclability.We present the synthesis of a Ni/Fe mixed oxide composite as anode material,obtained through the calcination at 400 °C (4 h) of a mixture containing aNi/Fe layered double hydroxide (Ni0.75Fe0.25(OH)2(CO3)0.125hydrotalcite) and a 2% of a natural clay sample collected from La Plata, Argentina.Previously, the double hydroxide was obtained by means of a coprecipitationmethod [1] in the presence of the natural clay. XRD analysis of the doublehydroxide and clay mixture before calcination shows the corresponding peaks ofthe hydrotalcite layered structure [1] as well as some signals related tokaolinite clay [2] (Figure 1.a). Cyclic voltammetry of the sintered mixtureexhibits a reduction peak located at 0.36, 0.50, 0.75, and 1.50 V in wellagreement with those reported for other NiO and Fe2O3 anodematerials [3] (Figure 1.b). Charge-discharge performance for the materialbefore and after calcination (without 2% natural clay) shows high initialdischarge capacities (>1000 mAh/g); nonetheless, a rapid capacity fade isobserved probably due to the well-known phenomenon of volumetric expansion(Figure 1.c). Cyclability of the Ni/Fe/clay oxide shows a considerableimprovement, with an initial discharge capacity of 2900 mAh g-1,reaching stability after 40 cycles on 576 mAh g-1 (Figure 1.d). Thecalcination and treatment of the natural clay in basic media could haveproduced an increase in its porosity, a specific surface acting as a bufferagainst the volumetric expansion in the Ni/Fe mixed oxide [4]