PENGARUH KOMBINASI ASAM OLEAT DAN PELARUT POLAR TERHADAP MORFOLOGI KATODA LIFEPO4 DENGAN METODE SOLID STATE REACTION

Muhamad Azka Nalindra, Prof. Dr. Harsojo, S.U., M.Sc.;Dr. Chotimah, M.Si.

2026 | Skripsi | FISIKA

Penelitian ini berhasil mensintesis material aktif LiFePO4 menggunakan metode solid state reaction dengan mengkaji pengaruh variasi penambahan surfaktan asam oleat dan pelarut polar etilen glikol terhadap morfologi dan struktur kristal yang dihasilkan. Sintesis LiFePO4 dilakukan menggunakan prekursor Li2CO3, NH4H2PO4, dan FeC2O4. Terdapat tiga variasi rasio molar surfaktan dan pelarut yang diaplikasikan, yaitu LFP-A (1:0,5), LFP-B (1:1), dan LFP-C (1:2). Karakterisasi morfologi dan komposisi unsur dilakukan menggunakan Scanning Electron Microscope (SEM) dan Energy Dispersive X-ray (EDX), sementara struktur kristal dan fasa dianalisis menggunakan X-ray Diffraction (XRD). Hasil karakterisasi SEM menunjukkan bahwa penambahan etilen glikol memengaruhi ukuran partikel material. Ukuran rata-rata partikel sampel variasi cenderung mengalami penurunan seiring meningkatnya konsentrasi pelarut, dengan nilai 1290 nm (LFP-A), 1100 nm (LFP-B), dan 855 nm (LFP-C). Namun, ukuran partikel pada seluruh sampel variasi masih lebih besar dibandingkan sampel kontrol LFP-0 sebesar 846 nm. Analisis XRD mengonfirmasi bahwa seluruh sampel memiliki struktur kristal olivin ortorombik dengan grup ruang Pnma (JCPDS 40-1499). Penambahan aditif mampu menekan intensitas puncak impuritas, namun menyebabkan derajat kristalinitas sampel variasi lebih rendah (±65%) dibandingkan sampel kontrol (86,70%), serta menghasilkan ukuran kristalit yang lebih besar (76-78 nm) dibandingkan sampel kontrol sebesar 47 nm. Secara keseluruhan, kondisi sintesis yang digunakan dalam penelitian ini menunjukkan bahwa penambahan etilen glikol dan asam oleat belum mampu menghasilkan kualitas fisik material yang lebih unggul dibandingkan sampel kontrol, sehingga diperlukan optimasi parameter sintesis lebih lanjut serta pengujian elektrokimia untuk memvalidasi performa material tersebut.

This study successfully synthesized LiFePO4 active material using the solid-state reaction method, examining the effect of varying additions of oleic acid surfactant and ethylene glycol polar solvent on the resulting morphology and crystal structure. LiFePO4 synthesis was carried out using Li2CO3, NH4H2PO4, and FeC2O4 as precursors. Three molar ratio variations of surfactant to solvent were applied, namely LFP-A (1:0.5), LFP-B (1:1), and LFP-C (1:2). Morphological and elemental composition characterization was performed using Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX), while crystal structure and phase were analyzed using X-ray Diffraction (XRD). SEM characterization results showed that the addition of ethylene glycol influenced the particle size of the material. The average particle size of the variation samples tended to decrease with increasing solvent concentration, with values of 1290 nm (LFP-A), 1100 nm (LFP-B), and 855 nm (LFP-C). However, the particle size of all variation samples remained larger than that of the control sample LFP-0, at 846 nm. XRD analysis confirmed that all samples possessed an orthorhombic olivine crystal structure with space group Pnma (JCPDS 40-1499). The addition of additives was able to suppress impurity peak intensity, but resulted in a lower degree of crystallinity for the variation samples (±65%) compared to the control sample (86.70%), as well as a larger crystallite size (76–78 nm) compared to the control sample of 47 nm. Overall, the synthesis conditions used in this study indicate that the addition of ethylene glycol and oleic acid has not yet succeeded in producing physical material quality superior to the control sample, so further optimization of synthesis parameters is needed, along with electrochemical testing to validate the material's performance.

Kata Kunci : LiFePO?, solid-state reaction, asam oleat, etilen glikol, kristalinitas