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Article 

Experimental investigation of cycling 

characteristics of anatase TiO2 nanotubes as 

negative electrode of lithium-ion batteries 
Simul Das1, Md. Arafat Rahman*1, Md. Saiful Islam2, Konok Chandra Bhowmik1  

1Department of Mechanical Engineering, Chittagong University of Engineering & Technology, Chittagong-4349, Bangladesh 
2Department of Nanomaterials and Ceramic Engineering, Bangladesh University of Engineering and Technology, Dhaka-

1000, Bangladesh 

A R T I C L E   I N F O 
 

Article history: 
Received 28 September 2024  
Received in revised form 
01 November 2024 
Accepted 14 November 2024 
 
Keywords: 
Anatase, TiO2, Nanotube, Anode,  
Lithium-ion Battery 
 
*Corresponding author 
Email address:  
arafat@cuet.ac.bd 
  
 
DOI: 10.55670/fpll.fuen.4.1.1 

A B S T R A C T 
 

Anatase TiO2 Nanotubes (NT-TiO2) is synthesized via electrochemical 
anodization of 99.9% pure titanium foils in a fluorine containing Ethylene 
Glycol (EG) electrolyte and used as the anode of lithium-ion batteries (LIBs). In 
the first cycle, the charge-discharge capacities are 550 mAhg-1 and 400 mAhg-1, 
respectively, with columbic efficiency of 75.75%. At 40th cycle, charge-discharge 
capacities are found to be 375 mAhg-1 and 325 mAhg-1, respectively, with 
improved columbic efficiency of 86%. The superior electrochemical 
performances of this type of battery originated from its high specific surface 
area and highly nanotubes structure. These advanced features of the nanotubes 
provide higher contact between electrodes and electrolytes, shorten the 
diffusion pathways for conductive ions. 
 

 
1. Introduction  

Lithium-ion batteries (LIBs) have emerged as a game-

changing technology in the search for effective and 

sustainable energy storage solutions. They have 

revolutionized modern portable electronics and made it 

possible to electrify several industries, including grid energy 

storage and transportation [1]. LIBs have replaced traditional 

energy storage systems because of their superior features, 

including high energy density, extended cycle life, and 

lightweight design for greater portability. The field of LIBs has 

observed continuous advancements in response to the 

increasing demand for energy storage systems with better 

performance metrics, such as higher energy density, quicker 

charging times, improved safety, and longer lifespans. In 

addition, the field of batteries for energy has witnessed 

considerable interest in the domain of nanofabrication. A 

multitude of materials for anodes have been identified, 

therefore instigating continuous investigations aimed at 

ascertaining feasible alternatives. The utilization of TiO2, a 

transition oxide of metals, as a material for anodes in batteries 

powered by lithium ions offers a potentially advantageous 

substitute for traditional graphite [2, 3]. The investigation 

into the use of TiO2 substances for anode applications may be 

traced back to the identification of the capability of lithium 

titanites to conduct lithium insertion activities. Recently, 

there has been a growing interest in exploring the potential 

Li-insertion properties of titanite spinels. This has led to a 

heightened focus on investigating different nanostructures of 

TiO2 polymorphs, specifically for their applicability in Li-ion 

battery systems. Rutile, which is considered the most 

thermally stable polymorph of TiO2, demonstrates a 

restricted ability to incorporate lithium ions, with a capacity 

of fewer than 0.1 lithium ions per unit of TiO2 at room 

temperature [4]. Li-reactivity was higher at a temperature of 

120C when using a polymeric electrolyte instead of a liquid 

electrolyte. In these conditions, the first discharge reversible 

capacities were reported to be 0.5 Li [2] and 1 Li [5] per 

formula unit of TiO2. It is noted that the diffusion of Li in rutile 

exhibits a significant degree of anisotropy, characterized by 

rapid diffusion primarily along the channels aligned with the 

c-axis [6-10]. The utilization of a well-aligned and self-

organized TiO2 nanostructure array presents a promising 

opportunity for its application as a potential anode material 

in LIBs. It is noted that difficulties observed in the utilization 

 

 

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S. Das et al. /Future Energy                                                                                                       February 2025| Volume 04 | Issue 01| Pages 01-07 

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of traditional graphite as a material for anodes in LIBs, such 

as the formation of SEI layers, dendritic effects, exfoliation 

over cycling, toxicity, and structural collapse [11, 12]. The 

primary impetus behind this research stems from the need to 

address these limitations and explore alternative anode 

materials that possess desirable properties, with the goal of 

proposing a potential replacement for conventional graphite 

anodes. Anatase TiO2 has a theoretical capacity of TiO2 is 

slightly lower (330mAhg-1) compared to graphite's capacity 

of 372mAhg-1; the focus of research has primarily been on the 

structural stability of TiO2. This work highlights the usage of 

anatase TiO2 nanotubes as the anode of LIBs. These 

nanotubes are created by anodizing pure Ti foils in a neutral 

fluoride solution, followed by calcination. Nanotube anatase 

structures with a significantly high specific area were created 

by carefully regulating the anodization and calcination 

processes. The primary cause of an interfacial process 

whereby lithium was stored on the surface of anatase 

particles was this sizable, exposed electrode area. The high 

specific surface area of anatase TiO2 nanotubes electrodes 

exhibits the first cycle charge-discharge capacities are 550 

mAhg-1 and 400 mAhg-1, respectively, with columbic 

efficiency of 75.75%. However, this electrode exhibited 

improved electrochemical performances of 375 mAhg-1 and 

325 mAhg-1, respectively, with improved columbic efficiency 

of 86% after 40th charge-discharge cycle. 

2. Experimental  

2.1 Fabrication of anatase TiO2 nanotubes 

Using a Pt plate as the cathode, 99.9% pure Ti foil was 

oxidized to create TiO2 nanotubes by the anodization process. 

The samples, particularly the Ti foils, were cleaned for 30 

minutes using distilled water and detergent water prior to 

anodization. After that, the samples were cleaned for ten 

minutes in a pure ethanol solution. Following that, a final 20-

minute acetone immersion rinse was performed. After that, 

the samples were dried for 24 hours at 105 oC. Two groups of 

all the Ti samples that needed to be anodized were created. 

One set of samples was cleaned with distilled water after 

being scraped with 0-grade emery paper. Both sets of Ti foils 

underwent anodization in a water-based solution that 

contained 0.5 wt.% NH4F + 1M (NH4)2SO4 + 10% of ethylene 

glycol (EG). Anodization took place in a 100 ml solution, 

indicating that the electrolyte comprised 100 ml of distilled 

water, 0.5g NH4F (supplied by SUEN STUDIO, China), and 

13.2g 1M (NH4)2SO4 (supplied by SUEN STUDIO, China). The 

anode and cathode were connected to the positive and 

negative terminals of the DC power supply, respectively. The 

DC power supply's positive and negative terminals were 

linked to the anode and cathode, respectively. A DC power 

supply (DAZHENG brand, model PS-3050, China) provided a 

steady 32 V DC voltage for one hour and two hours, 

respectively, while maintaining a zero-current flow.  

Figure 1. Visual representation of fabrication steps of anatase TiO2 nanotubes 



S. Das et al. /Future Energy                                                                                                       February 2025| Volume 04 | Issue 01| Pages 01-07 

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A magnetic stirrer hotplate ('78-1 Magnetic Stirrer 

Hotplate,' Yaeccc brand, China) at an average speed of 400 

rpm during the anodization process verified that the solutes 

in solution were mixed uniformly and that the ions were 

moving properly. Following anodization, the anodized section 

of Ti foils changed from having a grey appearance to a bluish 

one. After being cleansed with distilled water, all samples 

were put in a furnace and calcined for two hours at 550oC. The 

full process is depicted in Figure 1. 

2.2 Characterization 

The NT-TiO2 samples were analyzed using X-Ray Powder 

Diffraction (XRD) to obtain crystallographic information. To 

account for various scattering and random orientations, scans 

were conducted at different 2θ angles. Our analysis covered a 

2θ range from 10 o to 90 o with a step size of 0.05o, utilizing Cu 

Kα radiation (Empyrean, Panalytical-Netherlands) with a 

wavelength of ƛ = 1.5406Å. The morphological and 

compositional characterization of anatase TiO2 nanotubes 

was carried out using scanning electron microscopy and 

energy dispersive X-ray spectroscopy (SEM-EDX). For our 

experiment, SEM-EDX images were captured with a JSM 

7600F from JEOL (Japan) at 5.0 KV and various 

magnifications. 

2.3 Electrochemical performance test 

Coin cell battery case sets CR2032 (provided by Lith Co. 

China) were utilized for assembly purposes. Anode samples 

measuring 18 mm in diameter and 0.1 mm in thickness 

(approximately 2 cm²) of NT-TiO2, along with LiCoO2 coated 

aluminum sheet cathodes and a 20 mm battery grade PVC 

separator, fit perfectly into the cases. Both sides of the 

separator were saturated with a few drops of 1M LiPF6 (from 

Ximen Tmax Battery Equipment Ltd., China) electrolyte, 

which was mixed in ethylene carbonate (EC) and diethylene 

carbonate (DEC) at a ratio of 3:7. Finally, crimping was 

performed at a pressure of about 100 psi using a battery 

crimping machine (Metrology Lab, CUET). 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3. Results & discussion 

3.1 XRD analysis 

As illustrated in Figure 2, the X-ray diffraction (XRD) 

technique is used to analyze the phase purity and crystallinity 

of Ti and anatase TiO2 nanotubes. TiO2 has a tetragonal body-

centered crystal structure from space group I41/amd, and the 

lattice parameters for samples and Ti foil are a = 3.79 Å, c = 

9.51 Å. The anatase phase of TiO2 is confirmed by these data. 

Furthermore, the values match standard data (JCPDS Card no. 

21-1272) exactly. At diffraction 2θ angles of 39.910 (101 

plane), 52.770 (012 plane), and 70.4190 (013 plane), 

however, more noticeable anatase peaks are seen. The lack of 

any impurity phases within the detection range of the 

diffractometer indicates the purity of Ti. It is observed that no 

additional diffraction peaks related to the oxide phase were 

observed. Utilizing Scherrer's formula, D=0.9λ/B Cos(ϴ), with 

λ representing the X-ray wavelength in nanometers, B 

representing the full width at half maximum (FWHM) of 

peaks at 2θ, and θ representing the angle between the 

incident and diffracted beams in degrees, these diffraction 

data are entered.  Table 1 displays the crystal sizes of Ti foil 

and the synthesized anatase NT-TiO2 at various 2θ angles.   

3.2 SEM & EDX analysis 

The plan‐view SEM images and EDX spectra of anatase 

NT‐TiO2 is shown in Figure 3. Non‐uniform anatase NT‐TiO2 

arrays is grown by anodization, which is observed clearly 

underneath the Ti substrates as shown in Figure 3(a). The 

nanotubes are compact in this area. For the elemental 

characterization of the obtained nanotube layers, energy 

dispersive X-ray analysis is conducted. The EDX spectrum 

indicates the presence of the TiKa peak at 4.508 keV and O 

peaks at 0.525 keV as well as C peak at 0.277 keV in the 

anodized sample as shown in Figure 3(b). The obtained mass 

percentages of Ti and O is observed to be 55.30% and 42.44%, 

respectively, and the atom percentage of Ti, O, and C is 

28.93%, 66.81%, and 4.26%, respectively. It is noted that 

peak of carbon is found at 0.277 keV with the percentage of C 

is 2.04%.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 2. XRD patterns of different anatase NT-TiO2 along with pure Ti 



S. Das et al. /Future Energy                                                                                                       February 2025| Volume 04 | Issue 01| Pages 01-07 

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Table 1. Crystal Sizes Ti foil and as synthesized anatase NT-TiO2 

Sample 

No. 

 

Crystallographic Data for Pure Ti 

Average 

Crystal 

Size (nm) 

 

a 

2Ѳ 35.90 38.14 39.92 47.30 52.77 62.78 70.42 - - -  

38.27 B 0.22 0.32 0.23 0.20 0.26 0.22 0.33 - - - 

D 40.42 28.01 38.76 46.31 36.18 46.02 32.16 - - - 

  

Crystallographic Data of NT-TiO2 

 

 

b 

2Ѳ 22.87 25.37 27.51 36.21 38.47 40.23 47.61 53.06 63.07 70.71  

65.66 B 2.07 0.36 0.44 0.16 0.16 0.10 0.10 0.09 0.13 0.09 

D 4.21 24.39 20.09 56.26 58.35 89.19 92.14 111.45 80.33 120.18 

 

Figure 3. High magnification SEM image and EDX spectra of anatase NT-TiO2 



S. Das et al. /Future Energy                                                                                                       February 2025| Volume 04 | Issue 01| Pages 01-07 

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3.3 Electrochemical performance of anatase NT-TiO2 as 

anode of LIBs 

The galvanostatic charge-discharge cycle is carried out to 
measure the electrochemical performance of the as-prepared 
anatase NT-TiO2 anode. Figures 4(a & b) show the changes in 
current and voltage with respect to charge-discharge time. 
The cut-off voltage ranges are 4V-3.8V. It is noted that the 
voltages remain 2.5V at the beginning of the cycling, as shown 
in Figure 4(a). However, the voltage increases as the cycling 
moves forward, and after the 20th cycle, the voltage 
decreases.  In contrast, the voltage and current both increase 
at the end of the 40th cycle of the charge-discharge process, 
where the voltage is found to be 4.2V, as shown in Figure 4(b). 
Figure 4(c) shows a variation in the rate of change in charge 
with a change in voltage (dQ/dV) till 40 charge-discharge 
cycles for incremental capacity analysis, which identifies and 
quantifies changes in the electrochemical properties of the 
cell based on voltage measurements under constant current 
charge or discharge. It is observed that the phase transitions 
in the active electrode material anatase NT-TiO2 caused by the 
intercalation and deintercalation of lithium at about 2.5V 
correlate with the incremental capacity peaks. It is worth 
mentioning that dQ/dV analysis indicates the electrochemical 
performances of cell degradation over charge-discharge 
cycling, as shown in Figure 4(c), due to an increase in internal 
resistance [13]. Figure 5 shows the charge-discharge capacity 
and Columbic efficiency of LIB till 40 cycles. First cycle 
charge-discharge capacities are 550 mAhg-1 and 400 mAhg-1, 
respectively, with columbic efficiency of 75.75%, as shown in 
Figure 5(a). Higher initial capacities are ascribed to gel-like 
SEI layer formation by electrolyte decomposition [14]. In 
addition, the low columbic efficiency is attributed to unstable 
SEI formation, low reversible capacity, and electrolyte 
decomposition.  

 

 

However, in the subsequent 2nd cycle, the charge-
discharge capacity comparably reduced to 500 mAhg-1 and 
360 mAhg-1, respectively, due to the amorphous Li2O 
formation, which required a huge amount of lithium and 
caused the loss of lithium [2]. The increased columbic 
efficiency of 75.4% in the 2nd cycle is attributed to stable SEI 
layer formation. It is noted that the cell shows instability with 
fluctuating columbic efficiency, which is attributed to the 
larger volume expansion and pulverization effect of the 
anode. In addition, at the 27th cycle, the columbic efficiency is 
as high as 120%, as shown in Figure 5(b). This phenomenon 
is typical for transition metal oxides due to the pseudo 
capacitance [15-17]. At the 40th cycle, charge-discharge 
capacities are found to be 375 mAhg-1 and 325 mAhg-1, 
respectively, and the columbic efficiency is observed to be 
80%, which is comparable to the theoretical capacity of TiO2 
334 mAhg-1. Table 2 shows the comparison of charge and 
discharge capacities of this present work and previous work. 
It is noted that the charge-discharge capacities of this present 
work at 1st is observed to be 550 mAhg-1 and 400 mAhg-1, 
respectively, which is higher compared to 290 mAhg-1 and 
239 mAhg-1, respectively. However, the observed Columbic 
efficiency is slightly lower, 75%, compared to the previous 
work of 82%. This deficiency could be ascribed to the 
impurities in the electrolytes, and/or our cell is assembled in 
ambient without using a glovebox [18]. However, the 
electrochemical performances and Columbic efficiency 
increased after the 40th charge-discharge cycle compared to 
the previous work. Here, we are anticipating that the 
Columbic efficiency will be improved over a large number of 
cycling of our synthesized material since Columbic efficiency 
rises and irreversible capacity falls after the irreversible Li 
insertion sites are filled and trace water has been used up in 
the first cycles [14]. 

 

 

 Figure 4. Change of (a) Current (b) Voltage with respect to time from 1-20 Charge-Discharge cycles, c) Change of dQ/dV with respect to 

voltage from 1-40 cycles 



S. Das et al. /Future Energy                                                                                                       February 2025| Volume 04 | Issue 01| Pages 01-07 

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4. Conclusion 

Anatase TiO2 nanotube has been considered as one of the 

most attractive anode materials for lithium-ion batteries 

(LIBs) due to comparable energy density and life cycle 

compared to graphite. The nanotube features of 

nanostructure provide higher contact between binder-less 

electrode TiO2 and electrolytes, shorten the diffusion 

pathways for conductive ions and electrons that ensure faster 

kinetics. The work represents a facile fabrication of anatase 

NT-TiO2 via electrochemical anodization of Ti foils. Anatase 

NT-TiO2 is used as anode LIBs. Nanotubes provide a high 

surface area that allows for a higher electrode/electrolyte 

interface. Hence, lithium storage capacity is greatly enhanced 

compared to bulk amorphous TiO2. The cut-off voltage ranges 

are 4V-3.8V. It is noted that at the beginning of the cycling, the 

voltages remain at 2.5V. However, as the cycling moves 

forward, the voltage increases, and at the end of the 40th cycle 

of the charge-discharge process, the voltage is found to be 

4.2V. The battery exhibits excellent 1st cycle charge-discharge 

capacity of 550 mAhg-1 and 400 mAhg-1, respectively, with 

75.75% columbic efficiency. At the 27th cycle, the columbic 

efficiency is as high as 120%. This phenomenon is typical for 

transition metal oxide due to the pseudo-capacitance. At 

the 40th cycle, charge-discharge capacities are found to be 375 

mAhg-1 and 325 mAhg-1, respectively, and the columbic 

efficiency is found to be 86%. The findings showed that 

anatase TiO2 nanotubes' large surface area, short diffusion 

path, and quick kinetics make them promising electrode 

materials for LIB applications. 

 

 

 

 

 

 

 

 

 

 

 
Acknowledgments 
This work is financially supported by Chittagong University of 
Engineering & Technology (CUET), Bangladesh, through 
Research Grant no.: CUET/CHSR-43-43.8.6.  

Ethical issue 
The authors are aware of and comply with best practices in 
publication ethics, specifically concerning authorship 
(avoidance of guest authorship), dual submission, 
manipulation of figures, competing interests, and compliance 
with policies on research ethics. The authors adhere to 
publication requirements that the submitted work is original 
and has not been published elsewhere in any language. 

Data availability statement 
The manuscript contains all the data. However, more data will 

be available upon request from the corresponding author. 

Conflict of interest 

The authors declare no potential conflict of interest. 

References 

[1] Chy, M.N.U., et al., MXene as Promising Anode Material 

for High-Performance Lithium-Ion Batteries: A 

Comprehensive Review. 2024. 14(7): p. 616. 

[2] Rahman, M.A., et al., Improvement on electrochemical 

performances of nanoporous titania as anode of 

lithium-ion batteries through annealing of pure 

titanium foils. 2018. 27(1): p. 250-263. 

[3] Rahman, M.A., X. Wang, and C.J.J.o.E.C. Wen, Enhanced 

electrochemical performance of Li-ion batteries with 

Figure 5. Change of Specific capacity and columbic efficiency during (a) 1-20 and (b) 21-40 charge-discharge cycles at 1C current rating 

Table 2. Comparison of our work with previous work 

Compare Cycle No. Unit  Our Work Previous Work Reference 

Charge Capacity  

1st 

mAhg-1 550 290  

 

[19, 20] 

Discharge Capacity mAhg-1 400 239 

Columbic Efficiency  % 75 82 

Charge Capacity  

40th /Last 

mAhg-1 375 238 

Discharge Capacity mAhg-1 325 198 

Columbic Efficiency % 86 83 

 



S. Das et al. /Future Energy                                                                                                       February 2025| Volume 04 | Issue 01| Pages 01-07 

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nanoporous titania as negative electrodes. 2015. 

24(2): p. 157-170. 

[4] Kavan, L., M.J.E. Graetzel, and S.-S. Letters, Facile 

synthesis of nanocrystalline Li4Ti5 O 12 (Spinel) 

exhibiting fast Li insertion. 2001. 5(2): p. A39. 

[5] Kavan, L., D. Fattakhova, and P.J.J.o.t.E.S. Krtil, Lithium 

Insertion into Mesoscopic and Single‐Crystal TiO2 

(Rutile) Electrodes. 1999. 146(4): p. 1375. 

[6] Zachau-Christiansen, B., et al., Lithium insertion in 

different TiO2 modifications. 1988. 28: p. 1176-1182. 

[7] Macklin, W. and R.J.S.S.I. Neat, Performance of titanium 

dioxide-based cathodes in a lithium polymer 

electrolyte cell. 1992. 53: p. 694-700. 

[8] Koudriachova, M.V., N.M. Harrison, and S.W.J.S.S.I. de 

Leeuw, Diffusion of Li-ions in rutile. An ab initio study. 

2003. 157(1-4): p. 35-38. 

[9] Johnson, O.J.P.R., One-dimensional diffusion of Li in 

rutile. 1964. 136(1A): p. A284. 

[10] Koudriachova, M.V., N.M. Harrison, and S.W.J.P.R.L. de 

Leeuw, Effect of diffusion on lithium intercalation in 

titanium dioxide. 2001. 86(7): p. 1275. 

[11] Ruan, C., et al., Fabrication of highly ordered TiO2 

nanotube arrays using an organic electrolyte. 2005. 

109(33): p. 15754-15759. 

[12] Moradi, B. and G.G.J.J.o.A.E. Botte, Recycling of graphite 

anodes for the next generation of lithium ion batteries. 

2016. 46: p. 123-148. 

[13] Wang, R., et al., Degradation analysis of lithium-ion 

batteries under ultrahigh-rate discharge profile. 2024. 

376: p. 124241. 

[14] Munonde, T.S. and M.C.J.J.o.E.S. Raphulu, Review on 

titanium dioxide nanostructured electrode materials 

for high-performance lithium batteries. 2024. 78: p. 

110064. 

[15] Paul, S., et al., TiO2 as an Anode of high-performance 

lithium-ion batteries: A Comprehensive Review 

towards Practical Application. 2022. 12(12): p. 2034. 

[16] Zhang, Y., et al., Nanostructured TiO2‐Based Anode 

Materials for High‐Performance Rechargeable Lithium‐

Ion Batteries. 2016. 2(8): p. 764-775. 

[17] Paul, S., et al., Nanostructured anatase TiO2 as anode of 

high‐performance lithium‐ion batteries. 2022. 1(4): p. 

20220018. 

[18] Wang, L., S. Riedel, and Z.J.A.E.M. Zhao‐Karger, 

Challenges and Progress in Anode‐Electrolyte 

Interfaces for Rechargeable Divalent Metal Batteries. 

2024: p. 2402157. 

[19] Xu, J., et al., Electrochemical properties of anatase TiO2 

nanotubes as an anode material for lithium-ion 

batteries. 2007. 52(28): p. 8044-8047. 

[20] Jiang, Y., et al., Fabrication strategies for high-rate TiO2 

nanotube anodes for Li ion energy storage. 2020. 463: 

p. 228205. 

 

 
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