A study from the Department of Metallurgical and Materials Engineering, Universitas Indonesia, has successfully demonstrated that the addition of zinc oxide in the form of nanorods (ZnO nanorods) into lithium-ion battery anode materials can significantly improve battery durability.\nThe research, led by Dr. drg. Bambang Priyono, S.U., together with a team of researchers from Universitas Indonesia and the Indonesian Institute of Sciences (LIPI), was presented at the international conference i-TREC 2018.\nThe findings are straightforward yet significant: a ZnO composition of 4 wt% was found to be the most optimal, producing a capacity of 150.8 mAh\/g while maintaining performance under high charge-discharge rates of up to 20C.<\/p>\n\n\n\n
Lithium-ion batteries are now found everywhere. From smartphones and laptops to electric vehicles, nearly all modern devices rely on this technology.\nHowever, behind their widespread use lies a fundamental challenge that continues to concern engineers: conventional graphite-based anode materials are prone to degradation, especially when batteries are charged rapidly or operated under extreme conditions.<\/p>\n\n\n\n
One promising alternative candidate is lithium titanate, or Li\u2084Ti\u2085O\u2081\u2082, commonly known as LTO. This material offers excellent stability during charging and discharging processes and has a long cycle life.\nThe challenge is that LTO has low electronic conductivity. In other words, electrons cannot move easily through the material, limiting battery performance at high operating rates.<\/p>\n\n\n\n
This is where ZnO nanorods provide a potential solution.<\/p>\n\n\n\n
The research team synthesized ZnO nanorods by mixing zinc nitrate tetrahydrate and hexamethylenetetramine (HMTA) in cold water, followed by heating at 90\u00b0C for three hours.\nThe result was a nanoscale rod-shaped structure, significantly smaller than the width of a human hair.<\/p>\n\n\n\n
These ZnO nanorods were then incorporated into the LTO synthesis process using a sol-gel solid-state method.\nThe process involved multiple stages, beginning with TiO\u2082 gel formation, calcination at 300\u00b0C, and sintering at 750\u00b0C for three hours to produce the desired spinel LTO phase.\nThree ZnO compositions were tested: 4, 7, and 10 wt%.<\/p>\n\n\n\n
Characterization using X-ray Diffraction (XRD) confirmed that ZnO successfully entered the LTO structure across all variations.\nSEM-EDS analysis showed that ZnO was evenly distributed throughout the material, although particle sizes were not yet completely uniform due to an incomplete grinding process.<\/p>\n\n\n\n
Among the three tested variations, LTO\/ZnO 4% demonstrated the best performance in nearly all evaluations.<\/p>\n\n\n\n
Electrochemical Impedance Spectroscopy (EIS) testing showed that LTO\/ZnO 4% had the lowest charge-transfer resistance (Rct), measuring 76.05 \u03a9, compared with LTO\/ZnO 7% at 87.94 \u03a9 and LTO\/ZnO 10% at 83.85 \u03a9.\nLower resistance means electrons can move more easily, allowing the battery to operate more efficiently.<\/p>\n\n\n\n
Charge-discharge testing showed similar results. LTO\/ZnO 4% was able to maintain its capacity even at a 20C rate, something that could not be achieved by the 7% and 10% variations.\nThis finding is important for electric vehicle applications, which require rapid charging without sacrificing battery lifespan.<\/p>\n\n\n\n