[ABSTRAK
Sintesis serbuk Li4Ti5O12 yang didoping atom Al dan Na untuk material anodapada baterai ion lithium telah berhasil dilakukan dengan metode reaksi padat.Doping Al pada Li4Ti5O12 bertujuan untuk menaikkan konduktifitas ionik danmemperkuat struktur sedangkan doping Na bertujuan untuk menurunkan teganganoperasi. Pendopingan dilakukan dengan mengikuti persamaan Li(4-(x/3+y))AlxNayTi(5-2x/3)O12 (x=0; 0,025; 0,05; 0.075 dan y= 0;1) dimana atom Almensubtitusi Ti dan Li sedangkan atom Na mensubtitusi Li. Sintesis dilakukanmelalui metoda metalurgi serbuk dengan menggunakan Li2CO3, TiO2-anatase,Al2O3 and Na2CO3 sebagai bahan baku. Pada penelitian ini, pengaruh subtitusi Nadan Al dalam Li4Ti5O12 terhadap struktur, morphologi, ukuran partikel, surfacearea dan performa elektrokimia diteliti secara detil. Hasil penelitian menunjukkanbahwa doping ion Al pada Li4Ti5O12 tidak merubah struktur kristal Li4Ti5O12.Hasil FTIR menkonfirmasi tidak adanya perubahan struktur spinel pada guguskhas ketika didoping Al, dengan meningkatnya doping Al membuat tekstur butirmenjadi berpori, ukuran partikel menurun dengan ukuran terkecil 20,32 μm,surface area meningkat dengan nilai tertinggi 8,25 m2/gr, konduktifitas ionikmeningkat dengan konduktifitas terbaik adalah 8,5 x 10-5 S/cm, tegangan kerjasekitar 1,55 V dan kestabilan siklus terbaik diperoleh pada doping Al 0,025dengan kapasitas maksimum 70 mAh/g,. Sedangkan doping Na dalam Li4Ti5O12menyebabkan perubahan struktur dengan terbentuk 3 phasa baru yaitu NaLiTi3O7,Li4Ti5O12, dan Li2TiO3. Perubahan struktur juga dikonfirmasi dengan perubahangugus khas hasil analysis FTIR. Sedangkan kenaikan doping Al menyebabkanphasa NaLiTi3O7 semakin dominan, tekstur butiran menjadi halus, ukuran partikelmenurun dengan ukuran terkecil 30,89 μm, surface area menurun, konduktifitasionic stabil pada 2,5 x 10-5 S/cm, potensial kerja di 1,3 V dan 1,55V, kestabilanstruktur didapat pada doping Al 0,05 dengan kapasitas 90 mAh/g. Secarakeseluruhan menunjukkan bahwa penambahan doping Al mampu meningkatkankonduktifitas ionik dan kestabilan siklus dan doping Na menurunkan tegangankerja.

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ABSTRACT
Synthesis of Li4Ti5O12 powder doped by Al and Na atoms for lithium ion batteryanodes had been carried out using solid state reaction. Al doped on Li4Ti5O12 aimis to increase the ionic conductivity and strengthen the structure of Li4Ti5O12while Na doped aimed is to decrease the operating voltage. Al and Na doped onLi4Ti5O12 had been carried out by following equation Li(4 - (x / 3 + y))AlxNayTi(5-2x/3)O12 (x = 0; 0,025; 0.05, 0.075 and y = 0, 1) where the Al atoms substitute Tiand Li while Na substituting Li atoms. Synthesis is conducted through a solidstate reaction by using Li2CO3, TiO2-anatase, Al2O3 and Na2CO3 as raw materials.In this study, the effects of substitution of Na and Al in Li4Ti5O12 on the structure,morphology, particle size, surface area, and electrochemical performance weredeep studied. The results showed that the Al doped on the Li4Ti5O12 was notchange crystal structure of Li4Ti5O12. FTIR results confirmed that the absence ofchanges spinel structure in fingerprint region when doped Al, with increasing Aldoped make textures porous grains, particle size decreases to 20.32 μm, surfacearea increases with highest value of 8.25 m2/gr, conductivity is increased with thebest conductivity 8.5 x 10-5 S/cm, , the working voltage of about 1.55 V and thebest cycle stability was obtained on doping Al 0.05 and the maximum capacity is70 mAh/g. While doping Na in Li4Ti5O12 caused structural changes to the threephases formed NaLiTi3O7, Li4Ti5O12, and Li2TiO3. Tranformation on the structureis also confirmed by the changes in the fingerprint region with FTIR analysis.While the increase in Al doping causes NaLiTi3O7 phase become dominant,texture of granular becomes bigger and smoother, the particle size decreases to30.89 μm, surface area decreases, the ionic conductivity was stable at 2.5 x 10-5S/cm, The working potential in 1, 3 V and 1.55 V, the stability of the structureobtained on doping Al 0.05 and the maximum capacity of 90 mAh/g. Overallshowed that the addition of Al doped can improve the ionic conductivity whilestability of the cycle and the Na doped decrease the working voltage;Synthesis of Li4Ti5O12 powder doped by Al and Na atoms for lithium ion batteryanodes had been carried out using solid state reaction. Al doped on Li4Ti5O12 aimis to increase the ionic conductivity and strengthen the structure of Li4Ti5O12while Na doped aimed is to decrease the operating voltage. Al and Na doped onLi4Ti5O12 had been carried out by following equation Li(4 - (x / 3 + y))AlxNayTi(5-2x/3)O12 (x = 0; 0,025; 0.05, 0.075 and y = 0, 1) where the Al atoms substitute Tiand Li while Na substituting Li atoms. Synthesis is conducted through a solidstate reaction by using Li2CO3, TiO2-anatase, Al2O3 and Na2CO3 as raw materials.In this study, the effects of substitution of Na and Al in Li4Ti5O12 on the structure,morphology, particle size, surface area, and electrochemical performance weredeep studied. The results showed that the Al doped on the Li4Ti5O12 was notchange crystal structure of Li4Ti5O12. FTIR results confirmed that the absence ofchanges spinel structure in fingerprint region when doped Al, with increasing Aldoped make textures porous grains, particle size decreases to 20.32 μm, surfacearea increases with highest value of 8.25 m2/gr, conductivity is increased with thebest conductivity 8.5 x 10-5 S/cm, , the working voltage of about 1.55 V and thebest cycle stability was obtained on doping Al 0.05 and the maximum capacity is70 mAh/g. While doping Na in Li4Ti5O12 caused structural changes to the threephases formed NaLiTi3O7, Li4Ti5O12, and Li2TiO3. Tranformation on the structureis also confirmed by the changes in the fingerprint region with FTIR analysis.While the increase in Al doping causes NaLiTi3O7 phase become dominant,texture of granular becomes bigger and smoother, the particle size decreases to30.89 μm, surface area decreases, the ionic conductivity was stable at 2.5 x 10-5S/cm, The working potential in 1, 3 V and 1.55 V, the stability of the structureobtained on doping Al 0.05 and the maximum capacity of 90 mAh/g. Overallshowed that the addition of Al doped can improve the ionic conductivity whilestability of the cycle and the Na doped decrease the working voltage, Synthesis of Li4Ti5O12 powder doped by Al and Na atoms for lithium ion batteryanodes had been carried out using solid state reaction. Al doped on Li4Ti5O12 aimis to increase the ionic conductivity and strengthen the structure of Li4Ti5O12while Na doped aimed is to decrease the operating voltage. Al and Na doped onLi4Ti5O12 had been carried out by following equation Li(4 - (x / 3 + y))AlxNayTi(5-2x/3)O12 (x = 0; 0,025; 0.05, 0.075 and y = 0, 1) where the Al atoms substitute Tiand Li while Na substituting Li atoms. Synthesis is conducted through a solidstate reaction by using Li2CO3, TiO2-anatase, Al2O3 and Na2CO3 as raw materials.In this study, the effects of substitution of Na and Al in Li4Ti5O12 on the structure,morphology, particle size, surface area, and electrochemical performance weredeep studied. The results showed that the Al doped on the Li4Ti5O12 was notchange crystal structure of Li4Ti5O12. FTIR results confirmed that the absence ofchanges spinel structure in fingerprint region when doped Al, with increasing Aldoped make textures porous grains, particle size decreases to 20.32 μm, surfacearea increases with highest value of 8.25 m2/gr, conductivity is increased with thebest conductivity 8.5 x 10-5 S/cm, , the working voltage of about 1.55 V and thebest cycle stability was obtained on doping Al 0.05 and the maximum capacity is70 mAh/g. While doping Na in Li4Ti5O12 caused structural changes to the threephases formed NaLiTi3O7, Li4Ti5O12, and Li2TiO3. Tranformation on the structureis also confirmed by the changes in the fingerprint region with FTIR analysis.While the increase in Al doping causes NaLiTi3O7 phase become dominant,texture of granular becomes bigger and smoother, the particle size decreases to30.89 μm, surface area decreases, the ionic conductivity was stable at 2.5 x 10-5S/cm, The working potential in 1, 3 V and 1.55 V, the stability of the structureobtained on doping Al 0.05 and the maximum capacity of 90 mAh/g. Overallshowed that the addition of Al doped can improve the ionic conductivity whilestability of the cycle and the Na doped decrease the working voltage]