JFA (J URNAL FISIKA DAN APLIKASINYA) VOLUME 18, NUMBER 1, JANUARY 2022 Effect of Lanthanum Substitution on the Structure and Conductivity of LNMC Samples as Battery Cathodes M.P. Izaak*, 1 Y.E. Gunanto, 1 H. Sitompul, 1 and Y. Purwamargapratala 2 1 Department of Physics Education, University of Pelita Harapan Karawaci, Tangerang 15811, Indonesia 2 Center for Science and Technology of Advanced Materials, BATAN, Tangerang Selatan 15314, Indonesia Abstract: Lithium-Nickel-Manganese-Cobalt (LNMC) is one of the most successful types of lithium-ion batteries in the market. This battery is a combination of three main metals, nickel, manganese, and cobalt, with relatively the same composition. Measurements was performed on three LMNC materials combined with La composites to reduce the toxicity level of the Cobalt. The purpose of this research is to synthesize and characterize LMNC materials with certain La combinations, thus it is expected to be able to be used as battery cathode. Characterization of materials was carried out using XRD, SEM, and LCR-meter. In this study, we succeed in synthesizing and characterizing LMNC materials with a size of about 150-750 nm. The LCR-meter characterization found conductivity values of approximately 1.06×10 -3 , 7.07×10 -4 , and 4.05×10 -3 S/cm at 100 Hz, 2.29×10 -3 , 2.56×10 -3 , and 1.34×10 -2 S/cm at 2.5 MHz, 2.74×10 -3 , 3.04×10 -3 , and 1.51 ×10 -2 S/cm at 5 MHz for La dopping with x = 0.01, 0.03, and 0.05, respectively. The La substitution increases the conductivity value and reduces the particle size to nanoscale. Keywords: LMNC; La dopping; Cathode; Battery *Corresponding author: maya.izaak@uph.edu Article history: Received 23 September 2021, Accepted 29 January 2022, Published January 2022. http://dx.doi.org/10.12962/j24604682.v18i1.10902 2460-4682 c Departemen Fisika, FSAD-ITS I. INTRODUCTION Up till now, lithium (Li) ion is the main material for the cathode in the battery, while the material for the anode de- pends on the type of battery. The rechargeable ones use carbon, and the non-rechargeable ones use Li metal. For rechargeable Li ion-based batteries, the anode (carbon) acts as the negative pole and lithium ions serve as the cathode as well as the Li source. The reaction in it is not a redox reaction, it is the movement of Li ions through the electrolyte used. In this case, the materials usually used as cathodes are LiCoO 2 , Li-Mn-O, LiFePO 4 , and layered Li metal oxide [1]. Research on battery cathode materials made from Lithium- Nickel-Manganese-Cobalt (LNMC) has been intensively car- ried out by several researchers in recent years [2–19]. This is because the LNMC cathode material has high performance, a high-power density, a long life and meets safety standards [2– 19]. LNCM-based materials, namely LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM 111), are currently widely used as cathodes in electric vehicles and hybrid electric vehicles because of their high en- ergy density, long lifetime, and safety [2–19]. Increasing the energy density or ability can be done by adjusting the struc- ture and morphology [2, 3, 7, 8, 10, 11, 15]. Several studies have been carried out by substituting La in battery materials, including LiFePO 4 and CoFe 2 O 4 anode materials, showing an increase in battery conductivity and performance [20, 21]. To overcome the problems faced today, we conduct a study on Lithium-Nickel-Manganese-Cobalt (LNMC) mate- rials with La combinations to reduce the toxicity level of the cobalt. The purpose of this research is to synthesize and char- acterize LNMC materials with certain La combinations which are expected to be able to become battery cathode materials. II. METHOD Samples of LiNi 0.8 Mn 0.1 Co 0.1-x A x O 2 , with A = La, and x = 0.01; 0.03; and 0.05 as battery cathode materials, were made from Li(OH) 2 , Ni(OH) 2 , Mn(OH) 2 , Co(OH) 2 , and A(OH) 3 (A = La), each with purity more than 99%. The mixture of these materials was put in a stainless-steel vial and then pro- cessed through a solid-state reaction method using high en- ergy milling (750 rpm) for 10 hours. After that, it was heated at a temperature of 800 o C for 5 hours in the open air in the form of pellets pressed with a pressure of 5000 kg. X-ray diffractometer (XRD) Philips PW1710 type with Cu-Kα ra- diation and a wavelength of 1.5406 ˚ A at a diffraction angle of 2θ = 20- 80 o was used to characterize the phase formation and crystal structure formed. SEM JEOL-type, JED 2300, was used to see the shape and morphology of the granules. The electrical conductivity of the material was characterized by LCR-meter HIOKI-5020 type. III. RESULTS AND DISCUSSION Figure 1 shows the diffraction patterns of LiNi 0.8 Mn 0.1 Co 0.1-x La x O 2 samples with x = 0.01, 0.03, and 0.05. The results of the refinement using the GSAS program showed that all samples were not in a single phase. Some