Li-ion Hybrid Supercapacitors Research Articles

The Conversion of Li2SnO3 Li-Ion Hybrid Supercapacitors from Pastes Containing LiCl-SnCl2 Liquid Precursors Using an Atmospheric-Pressure Plasma Jet

We fabricate lithium tin-based oxide Li2SnO3 on carbon cloth from a gel-state precursor containing LiCl and SnCl2·2H2O using a nitrogen atmospheric-pressure plasma jet (APPJ). APPJ treatment provides both a high-temperature environment for the conversion of precursor into Li2SnO3 and nitrogen plasma reactive species for electrode surface modification. Here, the best electrochemical performance for the Li2SnO3 Li-ion hybrid supercapacitors (Li–HSCs) is achieved with 480 s of APPJ processing. The areal capacity of the 480 s APPJ-processed Li2SnO3 Li–HSCs reached 46.113 mC/cm2. The results indicate that APPJ is an effective tool for the rapid conversion processing of Li2SnO3 electrodes for Li–HSCs.

Li-Ni Metal Oxides Processed with Rapid Atmospheric-Pressure-Plasma Jet for Flexible Gel-Electrolyte Li-Ion Hybrid Supercapacitors

We use screen printing to deposit LiCl + Ni(NO3)2·6H2O pastes on a flexible carbon cloth substrate and then calcine it using a nitrogen atmospheric-pressure-plasma jet (APPJ). Through the high-temperature treatment by APPJ, pastes can be rapidly converted into Li-Ni oxides (LNOs). The LNOs on carbon cloth are then used as the electrodes of flexible gel-electrolyte Li-ion hybrid supercapacitors (Li-ion HSCs). The best areal capacity of 21.076 mC cm−2, as measured by cyclic voltammetry, is achieved by APPJ treatment at 620 °C for 480 s. To demonstrate the flexibility of the Li-ion HSCs, the Li-ion HSCs were bent at different curvatures to measure its performance. After bending test, the capacity remains >93% under bending with a curvature of up to 2 cm−1.

Pre-oxidation and catalytic carbonization strategies of hemp-derived multifunctional carbon for lithium-ion batteries/hybrid supercapacitors with high energy density and outstanding cyclability

Biomass-derived carbons (biochar) materials have attracted enormous attention owing to their fabulous performances, inherent structural advantages and cost-effectiveness. Herein, two kinds of biochar electrode materials of porous carbon cathode (KCT-800) and graphitic carbon anode (K-1300) were respectively prepared from a single waste biomass hemp stem core. KCT-800 with uniform 3D hierarchical porous structure and abundant adsorption sites was fabricated via mild pre-oxidation of KNO3 and catalytic carbonization of potassium citrate, delivers a reversible capacity 105 mAh g−1 at 100 mA g−1 without obvious capacity degradation after 6000 cycles under 5 A g−1. In addition, K-1300 sheet-like graphitic carbon anode material was also prepared via simple pre-oxidation and high temperature calcination at 1300 °C, which exhibits a reversible capacity 463 mAh g−1 at 0.2 A g−1 because of the N/O Co-doping natural heteroatom and enhanced the pseudo-capacitance. Furthermore, the Li-ion hybrid supercapacitors were assembled by KCT-800 cathode and K-1300 anode delivers a stunning energy density of 222 Wh kg−1 at 246 W kg−1 with a superior capacity retention of 90 % after 4000 cycles. This strategy not only provides a facile and environmental benign method to prepare biomass-derived carbon materials, but also offers new insights on bio-sources multi-functional energy storage materials.

Correction to: Matched MnO@C anode and porous carbon cathode for Li-ion hybrid supercapacitors

Correction to: Matched MnO@C anode and porous carbon cathode for Li-ion hybrid supercapacitors

Low-Pressure Argon/Hydrogen/Oxygen Plasma Treatment on LiMn2O4 Li-Ion Hybrid Supercapacitors

LiCl + Mn(NO3)2·4H2O pastes are screen-printed on a carbon cloth substrate and then calcined at 400 °C for 6 h in a tube furnace to convert them into LiMn2O4. Ar, Ar+5%H2, or Ar+5%O2 low-pressure plasma is then used to treat the LiMn2O4/carbon cloth. The treated LiMn2O4/carbon cloth is then used as the electrode for a Li-ion hybrid supercapacitors (Li-HSCs) with a three-electrode configuration in 1-M Li2SO4 liquid electrolyte. Ag/AgCl and Pt electrodes were used as reference and counter electrodes, respectively. Li-HSCs are characterized by galvanostatic charging/discharging, cyclic voltammetry, and electrochemical impedance spectroscopy. The results indicate that plasma treatment improves the Li-HSCs performance. In particular, Ar+5%O2 plasma treatment increases the areal capacity by ∼24% to 23.12 μA h cm−2. It also improves the coulomb efficiency and capacity retention rate of LiMn2O4 Li-HSCs.

Matched MnO@C anode and porous carbon cathode for Li-ion hybrid supercapacitors

Matched MnO@C anode and porous carbon cathode for Li-ion hybrid supercapacitors

ZnNiCo oxide/three-dimensional graphene electrode performance in propylene carbonate- and water-based Li-ion hybrid supercapacitors

ZnNiCo oxide (ZNCO)-decorated three-dimensional graphene (3DG) was synthesized using a hydrothermal process, and applied as the electrode material in water- and propylene carbonate (PC)-based Li-ion hybrid supercapacitor (LIHSC). The properties of the prepared composite (i.e., 3DG@ZNCO) were compared with those of pristine 3DG hydrogel (3DGH) and ZNCO, prepared separately using the same conditions. ZNCO particles formed in 3DG@ZNCO showed a smaller particle size than the pristine ZNCO, and their simultaneous growth with 3DGH resulted in a higher interlayer spacing in 3DG@ZNCO than 3DGH. 3DG@ZNCO provided considerably higher specific capacitance, cycling performance, and lower charge resistance than the individual pristine comprising components in both water- and PC-based LiClO4 electrolytes. However, higher differences were observed when PC-based LiClO4 electrolyte was used, and 3DG@ZNCO exhibited the specific capacitance of 62.5 F.g−1 at 40 mV.s−1, which was higher than that obtained in the water-based LiClO4 electrolyte. This was confirmed by the highest Li+ diffusion coefficient of 2.83 × 10−15 cm2.s−1 recorded for 3DG@ZNCO in PC. The 3DG@ZNCO-based LIHSC containing PC exhibited a significantly higher energy density of 81.2 Wh.kg−1 and power density of 5976 W.kg−1, which were about 228.7% and 225.3% higher than those obtained for the water-based LIHSC (i.e., 24.7 Wh.kg−1 at 1837 W.kg−1).

Hollow nanostructured NiO particles as an efficient electrode material for lithium-ion energy storage properties.

This work has developed a straightforward approach to obtaining NiO hollow structures by using Li2O2 as an easily removable template. The easy availability and electrochemically active nature of NiO have attracted researchers' attention as an anode electrode for Li-ion storage applications, including Li-ion secondary batteries (LIBs) and for Li-ion hybrid supercapacitors (LiHSCs; which offer higher power densities than LIBs without compromising energy density). However, NiO usage has been limited to its low reaction reversibility, poor conductivity, and conversion reaction capability. Recently, hollow nanostructured materials have attracted attention as efficient battery materials due to their fascinating structural features. This study presents a modified Li2O2-assisted method to obtain porous open 3D architectures of NiO nanostructures. The resultant hollow structures are electrochemically studied as an anode for a LIB, exhibiting excellent stability over hundreds of cycles. The result is recognized as one of the finest among NiO anodes reported. Also, NiO hollow structures studied as anodes for LiHSC devices fabricated with activated carbon cathodes exhibit an outstanding comprehensive electrochemical performance which is better than the typical LIB and supercapacitors.

LiMn2O4 Li-ion hybrid supercapacitors processed by nitrogen atmospheric-pressure plasma jet

LiCl–Mn(NO3)2·4H2O pastes were screen-printed on a carbon cloth substrate and furnace-calcined to convert them into LiMn2O4. The LiMn2O4 electrode was then post-processed using a nitrogen atmospheric-pressure plasma jet (APPJ). APPJ processing created oxygen vacancy defects on the electrode surface. Electrochemical tests of the Li-ion hybrid supercapacitors (Li–HSCs) were performed by cyclic voltammetry (CV) and galvanostatic charging/discharging (GCD) in 1-M Li2SO4 aqueous solution. The results indicate that proper APPJ treatment optimizes the Li–HSCs performance, whereas excessive APPJ treatment may cause material damage. After 3-min APPJ treatment at 620 °C, the Li–HSCs exhibited a maximum areal capacitance of 87.96 mF/cm2 with capacitance retention of 124.8% after a 1000-cycle CV test.

All vanadium-based Li-ion hybrid supercapacitor with enhanced electrochemical performance via prelithiation

We report on the fabrication of an all-vanadium based Li-ion hybrid supercapacitor whose performance is highly enhanced compared to either batteries or supercapacitors via prelithiation process. Orthorhombic vanadium oxide nanoparticles and amorphous vanadium phosphate nanosheets implemented with carbon nanotubes are applied to battery-type and capacitive electrode, respectively. By utilizing vanadium-based electrodes with different charge-storage mechanisms in one device, advantages of both supercapacitors and batteries can be achieved. After a simple short-circuit prelithiation, the fabricated hybrid supercapacitor exhibits a high electrochemical performance with a capacitance of 111.6 F g−1 at 10 mA g−1, operation voltage window of 3.2 V, energy density of 160.2 Wh kg−1 and power density of 4.484 kW kg−1. Furthermore, it retains 98.3% of its initial capacitance after 2000 charge-discharge cycles. Due to its high operation voltage, a single, fully-charged hybrid supercapacitor successfully lights up variously colored LEDs for longer than one hr. With energy stored in the hybrid supercapacitor, a fragmentized graphene foam based strain sensor is powered to monitor various body-movements. This study demonstrates the high potential of the vanadium-based Li-ion hybrid supercapacitor as a powerful energy storage device obtained via deliberate selection of materials and prelithiation process.

Facile Synthesis of Porous Hollow Cobalt‐Doped λ‐MnO2 Nano Architectures as a High‐performance Anode Material for Li‐ion Batteries and Li‐ion Hybrid Supercapacitors

AbstractThe cost‐effectiveness and easy availability of MnO2 have attracted researchers′ attention as an anode electrode for LIBs over other transition metal oxides. However, MnO2 usage has been limited to its low reaction reversibility and poor conversion kinetics. Besides, Li‐ion hybrid supercapacitors (LiHSCs) are in urgent demand which offers higher power densities than LIBs without compromising energy density. Among different polymorphs of MnO2, λ‐MnO2, due to its 3D spinel structure, can be applied in many applications. Usually, λ‐MnO2 can be obtained by extracting lithium from LiMn2O4 using complex electrochemical or acid leaching methods. This study presents a modified Li2O2 assisted method to obtain cobalt‐doped 3D architectures of λ‐MnO2 porous hollow nanostructures. The resultant MnxCo1‐xOy hollow structures with 5 % cobalt addition are used as anode for LIBs exhibited excellent charge reversibility and cycle stability over thousands of reaction cycles. This result is known to be one of the finest among MnO2 anodes reported to date. Also, a LiHSC device is fabricated with MnxCo1‐xOy hollow structures as anode and the device exhibits an excellent comprehensive electrochemical performance in terms of high operating voltage (4.2 V), with a specific cell capacity of 33 mAh g−1 at a high current density of 5 A g−1 and achieved the maximum power density of 12261 W kg−1 (with energy density at 81.7 Wh kg−1) with long cycle life.

All-solid-state electrochromic Li-ion hybrid supercapacitors for intelligent and wide-temperature energy storage

Newly proposed electrochromic Li-ions hybrid supercapacitors (ELHSs), incorporating energy storage and electrochromic functions into one hybrid system, provide huge potential for next-generation portable and intelligent electron devices. The critical next step in the future implementation is to explore a high-rate and stable battery-type electrochromic positive electrode to match the capacitive electrochromic negative electrode even under harsher environments. Herein, spinel LiMn2O4 electrodes coating with LiNbO3 thin layer (namely LMO@LNO) possess interconnected microstructures and multipores are successfully fabricated and severed as high-performance battery-type electrochromic positive electrode for ELHSs. The resulting LMO@LNO electrode exhibits remarkable electrochromic and energy storage performances, including large optical modulation (∼42.1%), high specific capacity (127.6 mAh g−1) and robust long-term electrochemical stability (over 1000 cycles). The Li-ion migration kinetics and electrochromic mechanism of the positive electrode are further comprehensively analyzed through experimental characterizations and density functional theory (DFT) calculations. By pairing with a transparent WO3 electrochromic capacitor-type negative electrode, an all-solid-state ELHS with a maximum working voltage of 2.3 V is assembled, delivering an impressive energy/power density (106.1 Wh kg−1/574.7 W kg−1) and admirable capacity retention of 83.5% after 3000 cycles. Significantly, the as-obtained ELHS with excellent environmental compatibility and reversible electrochromic performance even operate at progressively varying temperatures (RT ∼ 60 °C). This work provides a new opportunity to design next-generation safe and intelligent hybrid energy storage system for consumer electronics.

High-performance all-inorganic portable electrochromic Li-ion hybrid supercapacitors toward safe and smart energy storage

Li-ion hybrid supercapacitors (LHSs) bridged the gap between batteries and supercapacitors, and simultaneously attracted tremendous attention because of their potential applications in intelligent portable electronic devices. Nevertheless, obtaining all-inorganic LHSs with excellent environmental compatibility and smart display features remains a remarkable challenge. Herein, we designed and constructed a novel ultrathin all-inorganic electrochromic Li-ion hybrid supercapacitor (ELHS) by incorporating battery-type (LiMn2O4) and supercapacitor-type (WO3) electrochromic materials into one cell. The resultant ELHS achieved stable and reversible chromatic transitions during the electrochemical process, providing sufficient real-time information on the working status. Benefiting from the matching potential windows of the individual active electrodes and the all-inorganic construction of the whole device, the optimized ELHS exhibited an extended working voltage of 2.5 V. Impressively, the ELHS demonstrated an ultrahigh volumetric energy/power density (16.2 W cm−3/0.21 Wh cm−3) and remarkable cycling stability with ~95.4% capacitance retention after 5000 cycles. The observed performance characteristics outperformed most previously reported electrochromic energy storage devices and were comparable to some commercial devices. Significantly, inorganic electrolytes were introduced into the ELHS, which endowed it with outstanding environmental adaptability and ability to work at progressively varying temperatures (0–75 °C). We envision that this work may open new avenues for the development of next-generation safe and portable hybrid energy storage devices.

Comparison of organic electrolytes at various temperatures for 2.8 V–Li-ion hybrid supercapacitors

We explore different electrolytes containing lithium perchlorate (LiClO4) and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) salts in various solvents at different temperatures to associate the electrochemical stability of lithium titanium oxide (LTO)/lithium manganese oxide (LMO)-activated carbon (AC) composite Li-ion hybrid supercapacitors. By varying the solvents and operation temperature, we were able to detect a correlation between the electrochemical performance and the conductivity of each electrolyte. To test the electrochemical stability and longevity of the electrolytes in such a system, full-cells were analyzed via a voltage floating for 10 h at charged state (2.8 V) of the full-cell. Energy and power performance were the highest for acetonitrile (ACN) containing electrolytes due to their high lithium-ion conductivity. Additionally, the longevity of LiClO4 in 3-methoxypropionitrile (3-MPN) was superior to all tested electrolytes at ambient temperature with 97% capacity retention and energy efficiency of about 86% after 500 h of voltage floating. LiClO4 in a mixture of ACN and ethylene carbonate (EC) was the most stable electrolyte at high temperatures with 70% capacity retention after 500 h voltage floating at 60°C and 50% capacity retention after 250 h voltage floating. The longevity of LiTFSI in ACN and LiClO4 in 3-MPN electrolyte demonstrated a capacity retention of 97% and 92% after 500 h voltage floating, respectively, at low temperature (−10 °C).

Electrochemical Behavior Depending on Designed-Anode and Cathodes of Hybrid Supercapacitors

The performance of Li-ion hybrid supercapacitors (asymmetric-type) depends on many factors such as the capacity ratio, material properties, cell designs and operating conditions. Among these, in consideration of balanced electrochemical reactions, the capacity ratio of the negative (anode) to positive (cathode) electrode is one of the most important factors to design the Li-ion hybrid supercapacitors for high energy storing performance. We assemble Li-ion hybrid supercapacitors using activated carbon (AC) as anode material, lithium manganese oxide as cathode material, and organic electrolyte (1 mol L−1 LiPF6 in acetonitrile). At this point, the thickness of the anode electrode is controlled at 160, 200, and 240 μm. Also, thickness of cathode electrode is fixed at 60 μm. Then, the effect of negative and positive electrode ratio on the electrochemical performance of AC/LiMn2O4 Li-ion hybrid supercapacitors is investigated, especially in the terms of capacity and cyclability at high current density. In this study, we demonstrate the relationship of capacity ratio between anode and cathode electrode, and the excellent electrochemical performance of AC/LiMn2O4 Li-ion hybrid supercapacitors. The remarkable capability of these materials proves that manipulation of the capacity ratio is a promising technology for high-performance Li-ion hybrid supercapacitors.

Polycationic bimetallic oxide CoGa2O4 with spinel structure: dominated pseudocapacitance, dual-energy storage mechanism, and Li-ion hybrid supercapacitor application

In this work, the polycationic bimetallic oxide CoGa2O4 with spinel structure was successfully prepared by simple hydrothermal and subsequent calcination methods. Following, half-cell electrochemical test showed that this material presented a hybrid energy storage mechanism, namely combining Ga alloying and Co3O4 conversion. The combination of the two energy story mechanisms makes CoGa2O4 have higher conductivity than other single metal oxides. According to the calculation of the relationship between peak current and sweep speed, the b = 0.93 of CoGa2O4 is obtained, and its electrochemical behavior is closer to capacitive behavior than that of Co3O4 and NiCo2O4. This makes it have excellent rate performance and cycle stability. Consequently, the CoGa2O4//AC Li-ion hybrid supercapacitor (LIHSC) device exhibits excellent cycling stability (capacity retention of 83% after 8000 cycles), high-energy density of 111.5 Wh kg−1 (at 100 W kg−1), and high power density of 3927 W kg−1 (at 24 Wh kg−1).

Construction of T-Nb2O5 nanoparticles on/in N-doped carbon hollow tubes for Li-ion hybrid supercapacitors

In recent years, hybrid supercapacitors (HSCs) with good characteristics of both lithium batteries (LIBs) and supercapacitors (SCs) have become a hot research topic to meet the growing market demand for electric and hybrid electric vehicles. The key for high-performance HSCs is the reaction kinetics imbalance between the slow faradaic intercalation anode and fast non-faradaic physical adsorption/desorption cathode. Herein, we simultaneously grow ultrafine Nb2O5 nanoparticles on the inner walls and outer surface of hollow heteroatomic (N) carbon tube, giving a unique hierarchical hybrid nanostructure materials named T-Nb2O5@NC. The LIB test show its excellent high-rate capability and long-term cyclic stability. At current density of 0.25C (1.0–3.0 V, vs Li/Li+), the reversible specific capacity of this material is up to 194 mAh g−1. Importantly, the HSC device, assembled by T-Nb2O5@NC as anode and commercial activated carbon as cathode with an organic electrolyte, exhibits good electrochemical performance, including high energy density (49.7 Wh kg−1) and power density (8750 W kg−1), obviously superior to traditional HSC electrode materials. The results prove that T-Nb2O5@NC can be used as a promising HSC anode material.

High-performance Li-Ion hybrid supercapacitor based on LiMn2O4 in ionic liquid electrolyte

In this paper, we report a high-performance Li-ion hybrid supercapacitor (Li-HEC) based on LiMn2O4 in an imidazolium ionic liquid medium. The investigation of this type of cell is rare in the literature because hybrid devices constructed with ionic liquid (IL) are a challenge due to the coupling of distinct mechanisms (faradaic and electrostatic) of charge accumulation in a medium of high viscosity and low diffusion coefficient. The desire to overcome this challenge is motivated by the safety advantages brought by the usage of ILs as electrolytes, such as their low vapor pressure and non-flammability. Here, a spinel-LiMn2O4, with adequate morphology and tridimensional insertion/de-insertion mechanism, is applied as a faradaic electrode in order to maximize the energy density in a Li-HEC, while maintaining the highest power density of the electric double layer capacitors. Complete cells are optimized with a mesoporous carbon as a capacitive electrode and a 1 M lithium bis(trifluorosulfonyl)imide (LiTFSI)/1-ethyl-3-methylimidazolium bis(trifluoromethane)sulfonamide (EMITFSI) as electrolyte. Finally, we demonstrate that when compared to hybrid cells employing aqueous and organic electrolytes, this Li-HEC can rival their energy and power densities while maintaining excellent cycling stability.

Free-standing 3D composite of CoO nanocrystals anchored on carbon nanotubes as high-power anodes in Li-Ion hybrid supercapacitors

An effective strategy for constructing free-standing films of CoO nanocrystals and highly conductive carbon nanotubes as binder-free anodes for Li-ion hybrid supercapacitors is reported. Microstructure analysis reveals that the CoO nanocrystals with an average diameter about 20 nm are discretely and intimately anchored onto the surface of interconnected carbon nanotubes without agglomeration, thereby leading to approximately the entire surface of each CoO nanocrystal being available for electrochemical reactions. The unique free-standing nanocomposite not only provides a conductive network to increase conductivity and a protective buffer to accommodate volume variation, but also has large specific surface area and abundant active sites to result in an enhanced capacitive-controlled Li-storage behavior. In a half cell, the free-standing nanocomposite as an anode exhibits ultrahigh capacity and excellent cycling stability at temperatures of 0 °C, 25 °C, and 55 °C. Furthermore, a Li-ion hybrid supercapacitor is assembled using the free-standing nanocomposite as an anode and active carbon as the cathode and shows high-energy density (91 W h kg−1), high-power density (13.9 kW kg−1) and excellent capacity retention about 74% after 10000 cycles. Our results suggest great potential of the developed free-standing CoO-based composite in high-performance Li-ion hybrid supercapacitors.

Dual-ion hybrid supercapacitor: Integration of Li-ion hybrid supercapacitor and dual-ion battery realized by porous graphitic carbon

Abstract Lithium-ion hybrid supercapacitors (Li-HSCs) and dual-ion batteries (DIBs) are two types of energy storage devices that have attracted extensive research interest in recent years. Li-HSCs and DIBs have similarities in device structure, tendency for ion migration, and energy storage mechanisms at the negative electrode. However, these devices have differences in energy storage mechanisms and working potentials at the positive electrode. Here, we first realize the integration of a Li-HSC and a DIB to form a dual-ion hybrid supercapacitor (DIHSC), by employing mesocarbon microbead (MCMB)-based porous graphitic carbon (PGC) with a partially graphitized structure and porous structure as a positive electrode material. The MCMB-PGC-based DIHSC exhibits a novel dual-ion battery-capacitor hybrid mechanism: it exhibits excellent electronic double-layer capacitor (EDLC) behavior like a Li-HSC in the low-middle wide potential range and anion intercalation/de-intercalation behavior like a DIB in the high-potential range. Two types of mechanisms are observed in the electrochemical characterization process, and the energy density of the new DIHSC is significantly increased.