Lithium-ion Capacitors Research Articles

Hybrid storage system management for hybrid electric vehicles under real operating conditions

This study proposes the use and management of hybrid storage systems to power hybrid electric vehicles with the aim of reducing the negative effects of high current values on battery cycling life. Findings derive from a case study on a commercial plug-in hybrid electric vehicle with battery pack operations supported by a Lithium-ion Capacitor module. Specific experimental laboratory activities focused on the parametrization and validation of an equivalent circuit model representing the behavior of Lithium-ion capacitors for integration into the overall vehicle model (designed calibrated and validated on the basis of data from on-board data acquisition and measurement systems). The simulation platform was used to test various energy management strategies for the hybrid storage system supplying the vehicle during real driving cycles characterized by different operating conditions and driving styles. Results highlight the benefits of using the considered management strategies in terms of battery durability, allowing performance comparison for different driving routes and styles.

Roll-to-roll double side electrode processing for the development of pre-lithiated 80 F lithium-ion capacitor prototypes

Lithium-ion capacitors (LICs) show promise to help lithium-ion batteries (LIBs) and electrical double layer capacitors (EDLCs) in giving response to those applications that require an energy storage solution. However, pre-lithiation is a major challenge that needs to be tackled in order to develop efficient and long-lasting LIBs and LICs. In this work, we report for the first time the scale-up and utilization of sacrificial salts (dilithium squarate, Li2C4O4) as a pre-lithiation strategy in a LIC prototype fabricated in a pilot line. The synthesis of the sacrificial salt is scaled-up to produce 1 kg and is later incorporated in the positive electrode during the slurry formulation. After in-depth process optimization, 12 meter of a double side electrode are fabricated, achieving a high mass loading of 5.5 mg cm−2 for the HC negative electrode, and 14 mg cm−2 for the positive electrode accounting both the activated carbon and the dilithium squarate. On account of the satisfactory mechanical and electrochemical behaviour of the electrodes, multilayer pouch cell LIC prototypes are fabricated reaching 80 F each. Pre-lithiation is completed during the first ten cycles and after the required gas exhaustion, electrochemical performance of prototypes is also satisfactory. Moreover, fabricated pouch cells overcome a float test of 1600 h at 50 °C showing a capacitance retention of 84.3%. These results give clear evidence for the potential use of this strategy in real products and can foster research in the field to promote pre-lithiation by means of sacrificial salts as the final solution to the pre-lithiation step, both for LIBs and LICs.

Lithium-Ion Capacitors: A Review of Strategies toward Enhancing the Performance of the Activated Carbon Cathode

Lithium-ion capacitors (LiC) are promising hybrid devices bridging the gap between batteries and supercapacitors by offering simultaneous high specific power and specific energy. However, an indispensable critical component in LiC is the capacitive cathode for high power. Activated carbon (AC) is typically the cathode material due to its low cost, abundant raw material for production, sustainability, easily tunable properties, and scalability. However, compared to conventional battery-type cathodes, the low capacity of AC remains a limiting factor for improving the specific energy of LiC to match the battery counterparts. This review discusses recent approaches for achieving high-performance LiC, focusing on the AC cathode. The strategies are discussed with respect to active material property modifications, electrodes, electrolytes, and cell design techniques which have improved the AC’s capacity/capacitance, operating potential window, and electrochemical stability. Potential strategies and pathways for improved performance of the AC are pinpointed.

Metal-organic frameworks (MOFs)-derived Mn2SnO4@C anode based on dual lithium storage mechanism for high-performance lithium-ion capacitors

Lithium-ion capacitors (LICs) are an emerging energy storage device that combines high energy density with high power density. Tin dioxide (SnO2) is considered a promising anode material due to its high theoretical capacity and low redox potential. However, severe volume expansion limits its practical application. In this study, a rhombic-shaped Mn2SnO4@C composite material with a uniform carbon coating was synthesized through pyrolysis of metal–organic frameworks (MOFs) and employed as an anode material for LIC. The material exhibited a dual lithium storage mechanism through alloying and conversion reactions. The Mn2SnO4@C anode exhibited excellent cycling stability due to the synergistic effect between Mn and Sn, and the uniform carbon coating. The anode maintained a capacity retention over 100 % at various current densities and a specific capacity reached 944 mAh g−1 after rate testing. Furthermore, a novel LIC was assembled using Mn2SnO4@C anode and coconut shell biomass carbon (CSBC) cathode, delivering an ultrahigh energy density of 217.9 Wh kg−1 at 210 W kg−1 and maintaining 25.1 Wh kg−1 even at a high power of 21 kW kg−1. This work applied alloy-conversion dual lithium storage mechanism anode materials to LICs, providing a new avenue for next-generation high-performance LICs.

Utilizing Hydrolysate Derived from Biorefinery as a Carbon Coating Source for Silicon–Carbon Anodes in Lithium-Ion Capacitors

Utilizing Hydrolysate Derived from Biorefinery as a Carbon Coating Source for Silicon–Carbon Anodes in Lithium-Ion Capacitors

Pseudocapacitive lithium-rich disordered rock salt vanadium oxide with 3D lithium-ion transport pathways for high-performance lithium-ion capacitor

Pseudocapacitive materials with high-rate behavior of lithium-ion charge storage offer a pathway to narrow the kinetics gap with capacitive porous carbon cathode toward lithium-ion capacitors both with high energy and high power densities. However, most of pseudocapacitive materials are subject to their relatively high redox potential, thus resulting in an undesirable decrease in energy density. Here, we demonstrate that lithium-rich disordered rock salt vanadium oxide (DRX-Li3V2O5), electrochemically transformed from V2O5 bulk, exhibits typical pseudocapacitive behaviors within a low working potential range between 0.1 and 2.0 V (vs. Li/Li+). The pseudocapacitive behaviors of DRX-Li3V2O5 mainly arise upon a percolating network that offers three-dimensional Li + transport pathways confirmed by Monte Carlo simulations. When the V2O5 bulk precursor is replaced by V2O5 nanosheets, as-obtained DRX-Li3V2O5 electrode displays a nearly symmetrical cyclic voltammetry curve, suggesting an ideal pseudocapacitive behavior. A lithium-ion capacitor further assembled by this pseudocapacitive DRX-Li3V2O5 anode, yields a cell voltage of 4.0 V, a maximum energy density of 186 Wh kg−1 and a maximum power density of 51,680 W kg−1 as well as long-term cycling life over 30,000 cycles, which are higher than or comparable to that of the state-of-art lithium-ion capacitors based on graphite and other pseudocapacitive materials.

Unified model of lithium-ion battery and electrochemical storage system

Nowadays, energy storage systems are of paramount importance in sectors such as renewable energy production and sustainable mobility because of the energy crisis and climate change issues. Although there are various types of energy storage systems, electrochemical devices such as electric double layer capacitors (EDLCs), lithium-ion capacitors (LiCs), and lithium-ion batteries (LiBs) are the most common because of their high efficiency and flexibility. In particular, LiBs are broadly employed in many applications and preferred in the mobility sector, where there is a need for high energy and high power. To ensure good operating conditions for a battery and limit its degradation, it is important to have a precise model of the device. The literature contains numerous equivalent circuit models capable of predicting the electrical behavior of an LiB in the time or frequency domain. In most of them, the battery impedance is in series with a voltage source modeling the open circuit voltage of the battery for simulation in the time domain. This study demonstrated that an extension of a model composed exclusively of passive elements from the literature for EDLCs and LiCs would also be suitable for LiBs, resulting in a unified model for these types of electrochemical storage systems. This model uses the finite space Warburg impedance, which, in addition to the diffusion process of lithium\\lithium ions in the electrodes\\electrolyte, makes it possible to consider the main capacitance of the battery. Finally, experimental tests were performed to validate the proposed model.

Phytic acid mediated N, P co-doped hierarchical porous carbon with boosting capacitive storage for dual carbon lithium-ion capacitor

Lithium-ion capacitors (LICs) merged the energy characteristic of lithium-ion batteries and power characteristic of supercapacitors have aroused intensive attention. Nevertheless, the low capacity of capacitor-type cathode confines the development of LICs. Herein, an economic and efficient approach is developed to fabricate nitrogen and phosphorus co-doped hierarchical porous carbon (NP-HPC) by carbonizing cross-linked phytic acid and poly pyrrole/aniline precursor (PACP), in which phytic acid acts not only as a chemical crosslinker to regulate the precursor structure, but also a phosphorus source for dopant, thus providing more active sites for Li storage and enhancing structural stability. As-prepared NP-HPC cathode with enlarged specific surface area (∼2750 m2 g−1) and more micropores (∼1.410 nm) delivered a high specific capacity of 89 mAh g−1, with an ultrahigh capacity retention of 88.6% after 10000 cycles at 1.0 A g−1. DFT calculations demonstrated the co-dopant of N and P atoms synergistically improve the Li+ adsorption energy and electrochemical stability. More importantly, the assembled dual carbon LICs employing homologous NP-HPC and N, P co-doped spherical carbon (NP-SC) electrodes from the same precursor exhibit a maximum energy density of 121 Wh kg−1 at a power density of 92 W kg−1, with long-term cycling stability over 3000 cycles at 1 A g−1 with 80.2% retention.

Molten salts synthesis of Mo2C nanoflake and its composites for enhanced lithium-storage performance

The rational design of negative and positive materials to make them have satisfactory specific capacity and rate capability is an effective strategy to enhance the electrochemical properties of Lithium-ion hybrid capacitors (LIHCs). Herein, hierarchical MC-X (X = 0, 1, 2, 3) nanosheet composites were prepared by salt template-assisted solid-state synthesis strategy. Among them, Mo2C nanosheets are more dispersed on the amorphous carbon, and the close contact between them makes molybdenum carbide have enough buffer space during the intercalation and deintercalation of Li+, and makes MC-2 have a desirable specific surface area (SSA) of 341.1 m2/g. Electrochemical tests showed that the specific capacity of Mo2C remained at 313 mAh/g after 1000 cycles at 0.1 A/g, respectively. Meanwhile, the badam shell biochar (B) was prepared by KOH activation. The best sample (B-3) exhibited a high SSA of 3729.969 m2/g and high specific capacities of 265.6 mAh/g at 0.1 A/g, respectively. Furthermore, the constructed MC-2//B-3 LIHC exhibits high power density (4.68 kW kg−1), energy density (81.19 Wh kg−1), and excellent long-cycle stability. Therefore, the key to building a desirable property LIHC is to give consideration to the electrochemical performance between the positive and negative electrodes.

Li2C2O4 with 3D confinement as simultaneous sacrificial material and activation reagent of biomass-derived carbon for advanced lithium-ion capacitors

Inappropriate pore size distribution and the lack of a suitable lithium-cation source in the device are the key issues limiting the industrial application of biowaste carbon-based lithium-ion capacitors (LICs) to achieve both high energy density and power density for energy storage. Herein, the Li2O nanowires, decomposed from Li2C2O4 under three-dimensional confinement provided by wasted feather-derived carbon, are introduced as a sacrificial material for self-prelithiation activated carbon materials (prAC) cathode preparation with a high practical specific capacity of 1376 mAh/g. Accompanied by the in-situ formation of Li2O, the volume of mesopores increases significantly to 0.319 cm3/g (32.1 vol% of the total pore volume) by activation with CO2 yielded by the decomposition of Li2C2O4. The assembled prAC/graphite LIC demonstrates a high energy density of (122 Wh/kg at 220 W/kg) and a high power density (13 kW/kg at 30 Wh/kg), as well as a superior lifespan of 10,000 cycles at 1 A/g.

Eco-friendly production of carbon electrode from biomass for high performance Lithium and Zinc ion capacitors with hybrid energy storage characteristics

Biomass derived carbon has emerged as promising electrode material for supercapacitors, owing to its low-cost, abundance and eco-friendly nature. Herein, we investigate the application of fluorine-enriched carbon derived from Ipomoea carnea as electrode in Zinc-Ion and Lithium-Ion capacitors (ZIC and LIC). The prepared IC is activated using KOH to enhance the surface properties and to create an amicable environment to accommodate metal ions. The properties of resultant biomass carbon (IC) are evaluated using various physical and chemical characterization techniques. The activated IC exhibited high surface area of 736.7 m2/g and suitable porous structure. The IC electrode is paired with Zn metal foil and an aqueous solution of ZnSO4/MnSO4 is used to fabricate ZIC. The device exhibits a capacitance of 168 F g−1 and retains about 79.5% of its initial capacitance after 5000 cycles. The prepared IC pre-lithiated and used to fabricate Li Ion capacitor, which delivered a capacitance of 155 F g−1 and retained 77.5% of initial capacitance after 5000 cycles. The implication biomass-derived carbon in LIC and ZIC is experimented in detail.

Evaluating the feasibility of the spinel-based Li4Ti5O12 and LiNi0.5Mn1.5O4 materials towards a battery supercapacitor hybrid device

Hybrid devices consisting of energy-dense lithium-ion battery chemistry and power-dense supercapacitors in a single unit cell are vital to improve the energy density of supercapacitors. Herein, we demonstrate a lithium-ion capacitor containing a composite of LiNi0.5Mn1.5O4 and a high surface area carbon composite as the cathode and carbon-coated Li4Ti5O12 as an anode. The composite cathode combines redox and adsorption mechanisms to store ions, producing more capacity. In contrast, the nanostructure anode can store Li-ions through a faster diffusion-type intercalation process. As a result, the lithium-ion capacitor delivers energy densities of 48 and 30 Wh kg−1 at power densities of 250 and 7900 W kg−1, respectively. Furthermore, upon cycling at 1 A g−1, the full cell retains ∼70 % specific capacitance till 4000 cycles. The use of spinel materials in both electrodes boosts the electrochemical performances of this lithium-ion capacitor because of their inherent properties like stable phase and 3D network-type structure for Li-ion diffusion. Additionally, battery-type cathodes like LiNi0.5Mn1.5O4 (4.7 V vs. Li/Li+) with a wider potential window improve the energy density, whereas better safety and cycling stability arise from the zero-strain Li4Ti5O12 anode. The studies on impedance, self-discharge, and leakage current analyses prove the practical feasibility of the lithium-ion capacitor.

A universal strategy for producing 2D functional carbon-rich materials from 2D porous organic polymers for dual-carbon lithium-ion capacitors

Two-dimensional (2D) carbon materials have attracted enormous attention, but the complicated synthesis methods, inhomogeneous structure and uncontrollable properties still limit their use. Here we report a universal protocol for fabricating a series of heteroatom-doped 2D porous polymers, including pyrrole and indole as nitrogen-dopant sources, and 3,4-ethoxylene dioxy thiophene as a sulfur-dopant source by a simple chemical crosslinking reaction. This bottom-up strategy allows for the large-scale synthesis of functionalized ultrathin carbon nanosheets with a high heteroatom doping content and abundant porosity. Consequently, the obtained N-doped carbon-rich nanosheets (NCNs) sample has a specific capacity of 573.4 mAh g−1 at 5 A g−1 as an anode for lithium-ion capacitors (LICs), and the optimized sample has a specific capacitance of 100.0 F g−1 at 5 A g−1 when used as a cathode for a LIC. A dual-carbon LIC device was also developed that had an energy density of 168.4 Wh kg−1 at 400 W kg−1, while maintaining outstanding cycling stability with a retention rate of 86.3% after 10 000 cycles. This approach has the potential to establish a way for the precise synthesis of substantial amounts of 2D functionalized carbon nanosheets with the desired structure and properties.

Deciphering electrolyte dielectric extended electrochemical stability in lithium-ion capacitors

Deciphering electrolyte dielectric extended electrochemical stability in lithium-ion capacitors

Interface engineering of CoSe2/N-doped graphene heterostructure with ultrafast pseudocapacitive kinetics for high-performance lithium-ion capacitors

Interface engineering of CoSe2/N-doped graphene heterostructure with ultrafast pseudocapacitive kinetics for high-performance lithium-ion capacitors

Fabricating tunable metal sulfides embedded with honeycomb-structured N-doped carbon matrices for high-performance lithium-ion capacitors

Fabricating tunable metal sulfides embedded with honeycomb-structured N-doped carbon matrices for high-performance lithium-ion capacitors

Wearable high power flexible lithium-ion capacitors with adjustable areal loading

Wearable high power flexible lithium-ion capacitors with adjustable areal loading

A Tetrathiafulvalene-based Bimetal–Organic Framework for a Hybrid Lithium-Ion Capacitor: The Role of Bimetallic Centers in Charge Storage and Stability

A Tetrathiafulvalene-based Bimetal–Organic Framework for a Hybrid Lithium-Ion Capacitor: The Role of Bimetallic Centers in Charge Storage and Stability

PEDOT Nanowires Connecting Exfoliated HNb3O8 Nanosheets as High-Rate Anode for Lithium-Ion Capacitor

PEDOT Nanowires Connecting Exfoliated HNb₃O₈ Nanosheets as High-Rate Anode for Lithium-Ion Capacitor

Ti3C2Tx–Nb2Mo3O14 Composite as Novel Anode to Realize High Power Density Combined with High Stability in a Hybrid Lithium‐Ion Capacitor

Lithium‐ion capacitors (LICs), with their higher energy density at high power capability, stand out as the future generation of energy‐storage devices. Herein, the nanocomposite of Ti3C2Tx MXene with Nb2Mo3O14 is prepared by a one‐step hydrothermal method and studied as an electrode material for LIC. The as‐fabricated composite MXene niobium molybdenum oxide (MXNMO) achieves a high reversible capacity of 205 mAh g−1 at 100 mA g−1 current density with outstanding cyclability. Further, asymmetric LIC full‐cell device composed of MXNMO anode with supercapacitor grade activated carbon as a cathode delivers an energy density of 37.8 Wh kg−1 (0.25 A g−1) and a higher power density of 4244 W kg−1 (5 A g−1) along with the excellent durability showing 85% capacitance retention over 4000 cycles at 0.5 A g−1.