Alternative binder–free electrode based on facile deposition of carbon/graphene–TiO2 on the coin cell anode for a lithium–ion battery
Graphical abstract
Introduction
In the development of electronic devices such as electric vehicles (EVs) and hybrid electric vehicles (HEV), rechargeable lithium–ion batteries (LIB) have attracted significant attention due to their light weight and high energy density [1], [2], [3]. However, high cost and poor cycle stability are the major problems associated with the electrode materials of LIB. The stability of the electrode is related to the migration of Li–ions through the electrode–electrolyte interfaces [4]. In traditional electrodes, the polyvinyledine fluoride (PVDF) binder is used to attach the electrode materials to the current collector. Inevitably, the binder and current collector have no influence on the electrochemical performances, and they are detrimental to the energy density of LIB [5], [6]. Therefore, designing new types of electrode materials without using the binders and current collector is an essential goal [5], [6], [7], [8].
One of the easiest and most frequently applied methods for the fabrication of a binder–free electrode is by the deposition or growing of metal oxides of desirable morphologies on the nickel (Ni) foam [9], [10], [11]. In comparison to a traditional electrode, the direct contact between the anode material and current collector in the three–dimensional (3D) Ni–foam facilitates sufficient electronic and ionic transfer kinetics. In another approach, a TiO2 or CuO–based binder–free electrode is obtained by the engraving of their respective metal foils (Ti or Cu) [12], [13], [14]. The metal foils act as a continuous and fast conduction pathway for electrons. Due to the high cost and undesirable oxidation reactions of metal substrates, the flexible, high strength and electrically conductive carbon cloth is considered to be an alternative potential candidate for a binder–free electrode [15], [16], [17]. Barriers to the usage of metals or carbon–based binder–free electrodes have fallen dramatically since graphene has been developed as a processable colloidal suspension. Due to the excellent physical, mechanical and chemical characteristics of the 2–D G sheets, it allows the uniform deposition/growth of metal oxides (MO) on the basal plane and leads to a decrease in the aggregation/stacking of the MO/G nanocomposites [18], [19]. Recently, binder–free G/MO nanocomposites have been produced by layer–by–layer (LBL) assembly or by spin coating methods [7], [20], [21], [22], [23]. However, these processes are either complicated to scale up or have too high a cost for practical applications [24], [25]. In order to satisfy current energy needs, it is desirable to develop more effective and inexpensive synthesis methods for the binder and current collector in free porous LIB electrodes.
For the anode materials of LIB, the low cost, eco–friendly and highly stable structure of anatase TiO2 has long been considered as a promising candidate [5], [26], [27], [28], [29], [30], [31], [32], [33]. The morphology, crystal structure, crystallinity, and surface area are the important factors that determine the electrochemical performances of TiO2 [26], [34]. Nanostructured TiO2 increases the contact areas between electrode and electrolyte and leads to a decrease in the diffusion length of the Li–ions. Further, the high surface area and narrow pore size distribution of nanosized features of TiO2 increases the specific capacity, charge/discharge rates, and cycle stability of the LIB [34]. However, low electrical conductivity is a serious problem for TiO2–based active materials, which limits the charge transport characteristics of the electrode. In order to increase the electrical conductivity, the use of conducting materials such as carbon, graphene (G), or doping with metal atoms to TiO2 have been frequently studied [18], [35], [36], [37], [38], [39]. Among the conducting materials, 2D G has attracted a great deal of attention in LIB research due to its superlative, outstanding properties [18], [19]. 2D G acts as a strong conducting network for TiO2 and provides an efficient electrical contact between the active material and current collector. Hybrid nanocomposites of porous TiO2 and highly conductive G or carbon not only provide excellent performances in LIB, but also offer high performances in supercapacitor and photocatalytic activities [26], [40], [41]. Thus far, the binder–free TiO2 electrode has been obtained by the engraving or anodization of Ti foil [12], [42], [43], production of 3D cross–linked electrospun TiO2 nanofiber web [44], or with LBL assembly of GTiO2 [45]. Inevitably, these methods have a high cost and have limited potential for large scale production. In order to solve these issues, we alternatively developed simple, binder–free C/TiO2 and C/GTiO2 electrodes by directly depositing the active materials on the coin cell anode without using the binder and current collector. It is believed that direct deposition enables sufficient charge transition between the coin cell anode and active materials, which results in an improvement in the electrochemical performances.
Herein, the binder–free C/TiO2 or C/GTiO2 nanocomposites were prepared through the simultaneous carbonization and direct deposition of respective PMMA/TiO2 or PMMA/GO–TiO2 precursors on the coin cell anode. The obtained C/TiO2 and C/GTiO2 nanocomposites were strongly attached to the coin cell anode. The resulting nanocomposites exhibited high surface area and a highly satisfactory LBL arrangement of GTiO2 on the coin cell anode. The physical and electrochemical characteristics of the C/TiO2 and C/GTiO2 nanocomposites were thoroughly investigated. Drop testing of the fabricated electrode was conducted for systematically evaluating the binding efficiency of the C/TiO2 and C/GTiO2 nanocomposites on the coin cell anode. This binder–free electrode was fabricated with the use of cheap and readily available PMMA as a carbon source for attaching the TiO2 or GTiO2 on the coin cell anode. The fabrication method is simple, cost–effective, and could be useful to all MO based binder–free electrodes.
Section snippets
Materials and methods
Expandable graphite (Grade 1721) was purchased from Asbury Carbon (Grade 1721, Asbury, NJ, USA). Concentrated sulfuric acid (H2SO4), potassium permanganate (KMnO4), hydrochloric acid (HCl), and hydrogen peroxide (H2O2) were purchased from Samchun Chemical (Korea). The N, N–dimethylformamide (DMF) was obtained from SK chemicals (Korea). PMMA, Titanium (IV) n–butoxide was purchased from Sigma Aldrich (USA). All chemicals were used as received, without further purification.
Preparation of TiO2 and GO/TiO2 nanocomposite
TiO2 was prepared from
Results and discussion
The binder–free nanocomposite electrode was obtained through the calcination of the coin cell anode, which is loaded with PMMA/TiO2, PMMA/GO–TiO2–5, or PMMA/GO–TiO2–3 nanocomposite powders (Fig. 1). The PMMA starts melting with an increase in temperature and it decomposes to carbon when it reaches an elevated temperature (650 °C). The resulting carbon was deposited with TiO2 or GO–TiO2 on the coin cell anode. Interestingly, the carbon deposits act as a binder, which efficiently affords the
Conclusions
The electrodes were fabricated with the direct deposition of active materials on the coin cell anode using PMMA as a cheap carbon source. The inserted G has the additional benefits of providing an efficient conducting network, and improving the porous characteristics of the electrodes. In the LIB, the presence of large mesoporosity in the C/GTiO2 enhances the pseudocapacitive reaction with electrolytes, which results in a high specific capacity and excellent rate capability in comparison to
Acknowledgment
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (NRF-2016R1A2B2006311).
References (65)
- et al.
MnOx/SWCNT macro–films as flexible binder–free anodes for high–performance Li–ion batteries
Nano Energy
(2013) - et al.
Binder–free porous core–shell structured Ni/NiO configuration for application of high performance lithium ion batteries
Electrochem. Commun.
(2010) - et al.
Cupric oxide nanorods on double–face copper micropuzzles electrode as promising anode materials for lithium ion batteries
Int. J. Electrochem. Sci.
(2012) - et al.
Titanium dioxide@titanium nitride nanowires on carbon cloth with remarkable rate capability for flexible lithium–ion batteries
J. Power Sources
(2014) - et al.
Facile and fast synthesis of porous TiO2 spheres for use in lithium ion batteries
J. Colloid Interface Sci.
(2014) - et al.
Template–free synthesis of homogeneous yolk–shell TiO2 hierarchical microspheres for high performance lithium ion batteries
J. Power Sources
(2014) - et al.
The effect of diethylenetriamine on the solvothermal reactions of polyethyleneimine–graphene oxide/lithium titanate nanocomposites for lithium battery anode
J. Power Sources
(2015) - et al.
A facile nitridation method to improve the rate capability of TiO2 for lithium–ion batteries
J. Power Sources
(2014) - et al.
Flexible free–standing graphene–TiO2 hybrid paper for use as lithium ion battery anode materials
Carbon
(2013) - et al.
A facile one–pot synthesis of TiO2/nitrogen–doped reduced graphene oxide nanocomposite as anode materials for high–rate lithium–ion batteries
Electrochim. Acta
(2014)
A novel perspective on the formation of the solid electrolyte interphase on the graphite electrode for lithium–ion batteries
Electrochim. Acta
Analysis of effects of the state of charge on the formation and growth of the deposit layer on graphite electrode of pouch type lithium ion polymer batteries
J. Power Sources
The formation and stability of the solid electrolyte interface on the graphite anode
J. Power Sources
The effects of decomposition products of electrolytes on the thermal stability of bare and TiO2–coated delithiated Li1 − xNi0.8Co0.2O2 cathode materials
Electrochim. Acta
Advanced titania nanostructures and composites for lithium ion battery
J. Mater. Sci.
A carbon–coated TiO2(B) nanosheet composite for lithium ion batteries
Chem. Commun.
The role of nanotechnology in the development of battery materials for electric vehicles
Nat. Nanotechnol.
Recent advances in graphene and its metal–oxide hybrid nanostructures for lithium–ion batteries
Nanoscale
Novel approach toward a binder–free and current collector–free anode configuration: highly flexible nanoporous carbon nanotube electrodes with strong mechanical strength harvesting improved lithium storage
J. Mater. Chem.
Spin–coated silicon nanoparticle/graphene electrode as a binder–free anode for high–performance lithium–ion batteries
Nano Res.
Binder–free and carbon–free nanoparticle batteries: a method for nanoparticle electrodes without polymeric binders or carbon black
Nano Lett.
Synthesis of a nanowire self–assembled hierarchical ZnCo2O4 shell/Ni current collector core as binder–free anodes for high–performance Li–ion batteries
J. Mater. Chem. A
Three–dimensional Co3O4@MnO2 hierarchical nanoneedle arrays: morphology control and electrochemical energy storage
Adv. Funct. Mater.
Multifunctional TiO2–C/MnO2 core–double–shell nanowire arrays as high–performance 3D electrodes for lithium ion batteries
Nano Lett.
Engraving copper foil to give large–scale binder–free porous CuO arrays for a high–performance sodium–ion battery anode
Adv. Mater.
Spray–painted binder–free SnSe electrodes for high–performance energy–storage devices
ChemSusChem
Hierarchical MoS2 nanosheet/active carbon fiber cloth as a binder–free and free–standing anode for lithium–ion batteries
Nanoscale
Growth of TiO2 nanorod arrays on reduced graphene oxide with enhanced lithium–ion storage
J. Mater. Chem.
N–doped TiO2 nanotubes/N–doped graphene nanosheets composites as high performance anode materials in lithium–ion battery
J. Mater. Chem. A
Layer–by–layer assembled MoO2–graphene thin film as a high–capacity and binder–free anode for lithium–ion batteries
Nanoscale
Free–standing layer–by–layer hybrid thin film of graphene–MnO2 nanotube as anode for lithium ion batteries
J. Phys. Chem. Lett.
Free–standing and binder–free lithium–ion electrodes based on robust layered assembly of graphene and Co3O4 nanosheets
Nanoscale
Cited by (9)
Three-dimensional flexible molybdenum oxynitride thin film as a high capacity anode for Li-ion batteries
2022, Journal of Colloid and Interface ScienceCitation Excerpt :What’s more, adding non-conductive binders, such as polyvinylidene fluoride (PVDF), into the electrode materials will hinder ion diffusion and electron transfer, and thus increase the internal resistance of electrode. Compared with the traditional electrode, the thin film electrode without binder and conductive agent has the advantages of low production cost and stable electrochemical performance, and has become a recent research focus [19,20]. The preparation of three-dimensional (3D) flexible thin film electrode with non-binder is of great significance for the development of flexible mobile devices [19–22].
Photocatalytic oxidation of nitric oxide over AgNPs/TiO<inf>2</inf>-loaded carbon fiber cloths
2020, Journal of Environmental ManagementCitation Excerpt :However, it ought to be noted that, for the latter materials, the shape of the peak at ca. 26° was sharper. This feature was attributed to the overlapping effect of two different diffraction peaks, the first corresponding to the anatase phase TiO2, and second-ascribed to the amorphous carbon (Rajagopalan et al., 2017). Furthermore, the peaks located at 37.1, 48.0, 53.7, 54.9, 62.7, 68.7, 75.1° were also classified as anatase diffractions (JCPDS card no. 01-070-7348).
Characterization of Cu <inf>3</inf> N/CuO thin films derived from annealed Cu <inf>3</inf> N for electrode application in Li-ion batteries
2019, Thin Solid FilmsCitation Excerpt :However, there has been little research about the N doping in CuO electrode materials so far. What's more, the added nonconductive binders like polyvinylidene fluoride (PVDF) during electrode preparation increase the electrode resistance [20–22], thus directly preparing binder free flexible thin film electrodes is important in application of flexible mobile devices [23,24]. However, sol-gel method, hydrothermal method or other common method for N doping is difficult to fabricate binder free thin film electrode.
Graphene-based composite electrodes for electrochemical energy storage devices: Recent progress and challenges
2017, FlatChemCitation Excerpt :Titanium dioxide (TiO2), which has a fairly small theoretical specific capacity of 336 mA/g [205], has been developed as an anode material for LIBs due to its stability against electrolytes, non-toxicity and abundance in nature. Recently, various approaches such as one-pot simultaneous reduction in supercritical isopropanol [112], supersonic cold spraying [105], and binder-free facile deposition method [113] were suggested to fabricate TiO2/graphene composite electrodes. Poly (ρ-phenylenediamine)-reduced graphene oxide/lithium titanate (PρPDA-RGO)/Li4Ti5O12 (LTO) nanocomposites were prepared by I.-K. Yoo’s group [103].