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All Journal Jurnal Fisika Unand Jurnal Teknik Mesin International Journal of Social Science Journal of Innovation Research and Knowledge
Vamellia Sari Indah Negara
Jurusan Fisika FMIPA Universitas Andalas, Padang Kampus Unand Limau Manis, Pauh Padang 25163
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PENGARUH TEMPERATUR SINTERING KARBON AKTIF BERBASIS TEMPURUNG KEMIRI TERHADAP SIFAT LISTRIK ANODA BATERAI LITIUM Vamellia Sari Indah Negara; Astuti -
Jurnal Fisika Unand Vol 4 No 2: April 2015
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (815.216 KB) | DOI: 10.25077/jfu.4.2.%p.2015

Abstract

ABSTRAKSintesis material anoda baterai litium telah dilakukan dengan bahan baku dari litium hidroksida (LiOH) dan karbon aktif. Pembuatan karbon aktif dilakukan menggunakan aktivasi kimia dari arang kemiri dengan temperatur aktivasi 600 oC dan H3PO4 2,5% sebagai aktivator. Karbon aktif dikarakterisasi menggunakan SEM-EDS. Sintesis material anoda menggunakan metode sol-gel dengan variasi temperatur sintering 400 oC, 450 oC dan 500 oC. Material anoda dibuat dalam bentuk pellet dan dikarakterisasi menggunakan SEM, XRD, LCR meter dan Cyclic Voltammetry. Hasil SEM menunjukkan semakin tinggi temperatur sintering dihasilkan material yang lebih padat dengan pori-pori yang lebih kecil, sedangkan hasil XRD menunjukkan semua sampel memiliki fasa Li2CO3 dengan struktur kristal monoklinik. Konduktivitas listrik maksimum sebesar 1,0805x10-4 S/cm dan kapasitansi 198,6 μF yaitu pada sampel dengan temperatur sintering 450 oC.Kata kunci : baterai litium, arang kemiri, temperatur sinteringAbstractSynthesizing anode material of lithium battery has been done from lithium hydroxide (LiOH) and activated carbon. The manufacturing of activated carbon was done using chemical activation made fromcandlenut charcoal with an activation temperature was 600 °C and the activator was 2.5% H3PO4. Activated carbon was characterized using SEM-EDS. The anode material was synthesizedusing sol-gel method with variation of sintering temperature of 400 °C, 450 °C, and 500 °C. Anode material was manufactured in the form of pellets and characterized using SEM, XRD, LCR meters and Cyclic Voltammetry. SEM results show that thehigher sintering temperature, the denser material produced and the smaller pores size. The XRD results show that all samples haveLi2CO3 phase with monoclinic crystal structure. The maximum conductivity is 1.0805x10-4 S/cm and the capacitance is 198.6 μF at the sample with the sintering temperature of 450 °C.Keywords : lithium battery, charcoal hazelnut, sintering temperature
Studi Kelayakan Pemanfaatan PV sebagai Sumber Energi Ruang Pendingin Karkas Ayam Broiler Efendi, Mutiara; Hamzah, Reodhy; Indah Negara, Vamellia Sari; Araliz, Maheka Restu
Jurnal Teknik Mesin Vol 17 No 2 (2024): Jurnal Teknik Mesin
Publisher : Politeknik Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30630/jtm.17.2.1631

Abstract

When chicken prices drop, farmers often extend the harvesting period, which inevitably increases production costs. An alternative solution is to store chickens as carcasses in cooling storage. Indonesia has significant solar energy potential for the implementation of solar cooling storage technology to reduce electricity costs as a power source for cooling storage. This study aimed to analyze the economic feasibility of designing solar cooling storage with a one-ton carcass capacity. The research method involved analyzing the costs of implementing cooling storage by comparing the costs of electricity sourced from PLN, solar energy using PV, and extending the harvesting period by up to 10 days. The analysis results showed that the designed cooling storage had a capacity of 12 m³, and the production costs for storing carcasses using hybrid PLN and PV electricity were more efficient than using PLN electricity alone. This cost-saving approach is significantly more efficient than the production costs incurred when farmers extended the harvesting period. In terms of economic feasibility, the BEP values for PLN and PV electricity sources were 18.86 and 21.02 years, respectively. The calculations showed a BEP difference of approximately 5 years between PLN and PV electricity; however, economically, PV systems were more advantageous in the long term.
MINI REVIEW RECENT ADVANCES IN LIFEPO₄ CATHODE MATERIALS FOR LITHIUM-ION BATTERIES: SYNTHESIS, CHARACTERIZATION, AND PERFORMANCE OPTIMIZATION Vamellia Sari Indah Negara
Journal of Innovation Research and Knowledge Vol. 4 No. 7: Desember 2024
Publisher : Bajang Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.53625/jirk.v4i7.9627

Abstract

Lithium-ion batteries (LIBs) have revolutionized energy storage systems due to their high energy density, long cycle life, and wide range of applications. Among cathode materials, LiFePO₄ (LFP) has emerged as a promising candidate due to its excellent thermal stability, high safety, and long-term cycling performance. LFP features an olivine structure with a theoretical capacity of 170 mAh g⁻¹ and an operating voltage of approximately 3.4 V vs. Li/Li⁺, making it ideal for electric vehicles and renewable energy storage. However, its low electronic conductivity and slow lithium-ion diffusion present key challenges. Various strategies have been developed to overcome these limitations, including nanoengineering, doping, and conductive coatings. Synthesis methods such as sol-gel, solvothermal, and solid-state reactions have been employed to optimize particle structure and morphology. Characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray absorption spectroscopy (XANES and EXAFS) provide deep insights into the structural and electrochemical properties of LFP. This study highlights recent advances in LFP materials and optimization strategies to enhance its performance for next-generation battery applications.
PENGARUH TEMPERATUR SINTERING KARBON AKTIF BERBASIS TEMPURUNG KEMIRI TERHADAP SIFAT LISTRIK ANODA BATERAI LITIUM Indah Negara, Vamellia Sari; -, Astuti
Jurnal Fisika Unand Vol 4 No 2: April 2015
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jfu.4.2.%p.2015

Abstract

ABSTRAKSintesis material anoda baterai litium telah dilakukan dengan bahan baku dari litium hidroksida (LiOH) dan karbon aktif. Pembuatan karbon aktif dilakukan menggunakan aktivasi kimia dari arang kemiri dengan temperatur aktivasi 600 oC dan H3PO4 2,5% sebagai aktivator. Karbon aktif dikarakterisasi menggunakan SEM-EDS. Sintesis material anoda menggunakan metode sol-gel dengan variasi temperatur sintering 400 oC, 450 oC dan 500 oC. Material anoda dibuat dalam bentuk pellet dan dikarakterisasi menggunakan SEM, XRD, LCR meter dan Cyclic Voltammetry. Hasil SEM menunjukkan semakin tinggi temperatur sintering dihasilkan material yang lebih padat dengan pori-pori yang lebih kecil, sedangkan hasil XRD menunjukkan semua sampel memiliki fasa Li2CO3 dengan struktur kristal monoklinik. Konduktivitas listrik maksimum sebesar 1,0805x10-4 S/cm dan kapasitansi 198,6 μF yaitu pada sampel dengan temperatur sintering 450 oC.Kata kunci : baterai litium, arang kemiri, temperatur sinteringAbstractSynthesizing anode material of lithium battery has been done from lithium hydroxide (LiOH) and activated carbon. The manufacturing of activated carbon was done using chemical activation made fromcandlenut charcoal with an activation temperature was 600 °C and the activator was 2.5% H3PO4. Activated carbon was characterized using SEM-EDS. The anode material was synthesizedusing sol-gel method with variation of sintering temperature of 400 °C, 450 °C, and 500 °C. Anode material was manufactured in the form of pellets and characterized using SEM, XRD, LCR meters and Cyclic Voltammetry. SEM results show that thehigher sintering temperature, the denser material produced and the smaller pores size. The XRD results show that all samples haveLi2CO3 phase with monoclinic crystal structure. The maximum conductivity is 1.0805x10-4 S/cm and the capacitance is 198.6 μF at the sample with the sintering temperature of 450 °C.Keywords : lithium battery, charcoal hazelnut, sintering temperature
OPTIMIZATION OF POWER CONTROL TO ENSURE STABLE ELECTRICITY SUPPLY IN MICRO-HYDRO POWER PLANT Nota Effiandi; Rahmat Hafiz; Mutiara Efendi; Vamellia Sari Indah Negara; Reodhy Hamzah
International Journal of Social Science Vol. 5 No. 4 (2025): December 2025
Publisher : Bajang Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

A This study proposes an optimization-based power control strategy to enhance voltage and frequency stability in micro-hydro power plants (MHPP). The approach integrates multi-objective optimization, adaptive control, predictive algorithms, and robust mechanisms to overcome instability caused by load and water flow variations. System modeling and simulation were performed in MATLAB/Simulink, followed by experimental validation on a laboratory-scale prototype. Results show significant improvements compared to conventional PID and fixed-gain Electronic Load Controllers (ELC), reducing voltage and frequency deviations by up to 69% and 67%, respectively. Total Harmonic Distortion (THD) decreased to 3.8%, power factor improved to 0.93, and overall efficiency reached 87.2%. The method proved effective, stable, and feasible for real-time microcontroller implementation, offering a reliable solution for isolated and rural MHPP systems.
Co-Authors Araliz, Maheka Restu Astuti - Astuti Astuti Efendi, Mutiara Hamzah, Reodhy Mutiara Efendi Nota Effiandi Rahmat Hafiz Reodhy Hamzah