Sintesis dan Karakterisasi Material Aktif Katoda LiFeSixP1-xO4/C dengan Variasi Doping Ion Si (0<x<0,15)

Material aktif katoda LiFeSixP1-xO4/C dengan doping ion Si x= 0, 0,05, 0,1, dan 0,15 telah berhasil disintesis dengan metode solid-state reaction dengan bahan dasar komersial LiOH.H2O, H3PO4, Fe2O3, dan SiO2.H2O. Dilakukan proses kalsinasi dengan temperature 700 oC selama 2 jam dan disinterring dengan temperature 900 oC selama 6 jam dalam lingkungan gas inert N2. Hasil dari proses sintering kemudian dicoating carbon dengan perbandingan 2%wt tepung tapioka dan 8%wt asam asetat dari berat LiFePO4 dengan pembakaran dalam temperatur 700 oC selama 20 menit. Material aktif katoda dikarakterisasi melalui X-ray Diffraction (XRD), Scanning Electron Microscope – Electron Dispersion Xray (SEM-EDX) pada lembaran katoda, Cyclic Voltammetry (CV), dan Charge/Discharge (CD). Hasil analisis XRD menunjukkan bahwa terbentuk 100% fasa olivine LiFePO4. Penambahan konsentrasi doping ion Si tidak berpengaruh secara signifikan terhadap kapasitas baterai. Nilai kapasitas terbesar dan performa yang baik pada sampel dengan variasi x=0,15. Berdasarkan uji setengah sel, kapasitas pada saat discharging sebesar 35, 51 mAh/g pada 0,1C dengan cycle life terbaik pada rentang tegangan pengujian 2,5 – 4,2 Volt. ========================================================================================================== Active cathode material of LiFeSixP1-xO4/C with Si ion doped with x = 0, 0,05, 0,1, and 0,15 has successfully synthesized by a solid-state reaction method with LiOH.H2O, H3PO4, Fe2O3, and SiO2.H2O as the commercial materials. The materials were put in calcination temperature in Nitrogen environment at 700 oC with holding time in 2 hours, then sintered at temperature 900 oC in 6 hours in Nitrogen environment. The material coated by carbon from tapioca and acetic acid mixed with weight ratio 2%wt and 8%wt then burned at temperature 700 oC in 20 minutes in Nitrogen environment. Characterization was performed using X-ray Diffraction (XRD), Scanning Electron Microscope – Electron Dispersion Xray (SEM-EDX)) on the cathode sheet, Cyclic Voltammetry (CV), and Charge/Discharge (CD). The results show that the samples has olivine phase. Si ions doped in LiFePO4 are not significantly enhancing the specific capacity. The largest capacity and the excellent performance is in the sample with x=0,15. Based on half-cell testing, the sample achieve a specific discharge capacity of 35,51 mAh/g at 0,1C rate with an excellent cycle life in the usual cycling voltage range 2,5 – 4,2 Volt