Performance Of Lithium-ion Capacitors Research Articles

Designing electrolytes for enhancing stability and performance of lithium-ion capacitors at large-scale cylindrical cells

This study investigates the impact of fluorinated ethylene carbonate (FEC) as a co-solvent in the electrolytes of large-scale lithium-ion capacitors (LICs), an area previously unexplored. Our comprehensive analysis integrates electrochemical analysis, gas detection, and surface chemical examination to assess the performance and stability of a 1.2 M LiPF6 electrolyte system. We explored various formulations, including a standard EC/EMC/DEC mixed solvent and newly designed electrolytes with FEC additions, such as EC/EMC/DEC/FEC and DMC/FEC blends. Our findings demonstrate that the DMC/FEC blend matches and even surpasses the capacity retention of traditional electrolytes, suggesting enhanced long-term stability. FEC's presence significantly reduces electrolyte decomposition, as confirmed by in situ Differential Electrochemical Mass Spectrometry and ex-situ gas chromatography. Further, surface chemical analysis highlighted the formation of a stable, LiF-rich solid electrolyte interface (SEI) when FEC is included, thereby improving the chemical stability of the system. These results underline FEC's crucial role in optimizing electrolyte compositions, thus advancing the development of more efficient and durable LIC systems. FEC's integration into LIC electrolytes represents a significant breakthrough, enhancing overall performance and longevity, with broad implications for the application of LICs in various technologies.

MOF-derived porous graphitic carbon with optimized plateau capacity and rate capability for high performance lithium-ion capacitors

MOF-derived porous graphitic carbon with optimized plateau capacity and rate capability for high performance lithium-ion capacitors

Novel high entropy oxide as anode for high performance lithium-ion capacitors

A fresh type of lithium-ion battery anode called high entropy oxide (HEO) has a remarkable specific capacity and outstanding cycle performance. The advantage of HEO consists in the distinct adjustable contents along with governable chemical constitution, which makes it possible to develop novel electrode materials using infinite combinations of elements. We successfully synthesized (FeCoNiCuZn)3O4 material via a straightforward hydrothermal way in this work. At a lofty current density of 1 A g−1, obtaining an invertible capacity of 540 mAh g−1 behind 500 cycles, the unique structure of (FeCoNiCuZn)3O4 exhibits remarkable stability. We analyzed the valence states of the metal elements and further investigated their relationship with electrochemical and kinetic properties after using X-ray photoelectron spectroscopy (XPS). Subsequently, by incorporating the (FeCoNiCuZn)3O4 anode with activated carbon (AC) in a lithium-ion hybrid capacitor (LIHC), which could deliver an outstanding power density of 4000 W kg−1 and energy density of 158 Wh kg−1 while maintaining excellent capacity retention property even after 5000 cycles, the anode showed considerable performance. This is the first time HEO has been used in LIHC, as far as we are aware.

High mass-loading N-rGO-T-Nb2O5/CuNW composite membrane for high-rate lithium-ion capacitor anodes

High-performance lithium-ion capacitors (LICs) show tremendous application prospects in new energy vehicles and portable electronic devices due to their excellent electrochemical properties. However, the low active mass loading and poor reaction rate of the current anode seriously limit the rate performance of LIC. Herein, we developed a high mass-loading N-doped reduced oxide graphene (N-rGO)-T-Nb2O5/Copper nanowire (CuNW) (GNC) composite membrane as an anode for high-rate LICs, which was obtained by compressing the corresponding 3D composite aerogel. Importantly, Li+ can be rapidly embedded/detached in large lattice spacing of T-Nb2O5 and high adsorption capacity of N-rGO, improving the rate performance of the GNC anode. Furthermore, the use of trace CuNWs conductive network instead of conventional Cu foil can effectively reduce the self-weight of the composite membrane for enhancing the specific capacity of the electrode. In lithium-ion half-cell, the high mass-loading GNC-2 (6.19 mg·cm−2 in coin cell) possessed high specific capacity, large rate performance, and excellent cycling life. The LIC consisted of prelithiated GNC-2 and N-rGO exhibited high energy density (173.9 Wh·kg−1), and power density (5242.8 W·kg−1) with outstanding cycle stability (capacitance retention rate of 93.2 % after 10,000 cycles at 3 A·g−1).

Carbon Nano-Onion-Encapsulated Ni Nanoparticles for High-Performance Lithium-Ion Capacitors

Lithium-ion capacitors (LICs) feature a high-power density, long-term cycling stability, and good energy storage performance, and so, LICs will be widely applied in new energy, new infrastructure, intelligent manufacturing. and other fields. To further enhance the comprehensive performance of LICs, the exploration of new material systems has become a focus of research. Carbon nano-onions (CNOs) are promising candidates in the field of energy storage due to the properties of their outstanding electrical conductivity, large external surface area, and nanoscopic dimensions. Herein, the structure, composition, and electrochemical properties of carbon nano-onion-encapsulated Ni nanoparticles (Ni@CNOs) have been characterized first in the present study. The initial discharge and charge capacities of Ni@CNOs as anodes (in half-cells (vs. Li)) were 869 and 481 mAh g−1 at 0.1 A g−1, respectively. Even at a current density of 10 A g−1, the reversible specific capacity remained at 111 mAh g−1. Ni@CNOs were used as anode materials to assemble LICs (full pouch cells (vs. activated carbon)), which exhibited compelling electrochemical performance and cycle stability after optimizing the mass ratio of the positive and negative electrodes. The energy density of the LICs reached 140.1 Wh kg−1 at 280.2 W kg−1 and even maintained 76.6 Wh kg−1 at 27.36 kW kg−1. The LICs also demonstrated excellent cycling stability with a 94.09% capacitance retention over 40,000 cycles. Thus, this work provides an effective solution for the ultra-rapid fabrication of Ni-cored carbon nano-onion materials to achieve high-performance LICs.

Structure optimization of solvent-free Li4Ti5O12 electrodes by electrostatic spraying for lithium-ion capacitors

The manufacturing processes of electrodes have a prominent influence on the cost and performance of lithium-ion capacitors (LICs), which are limited by the conventional wet-coated method due to the usage of solvent. Herein, the solvent-free Li4Ti5O12 (LTO) electrodes are prepared with electrostatic spraying deposition using for LICs. Owing to the solvent being avoided during the manufacturing, the dry-sprayed electrode exhibits a higher porosity (∼40%) than that of the wet-coated electrode (∼30%), together with a larger electrochemically active surface area. The optimized microstructure improves electrolyte infiltration and offers effective Li-ion transport paths, which reduces the electrochemical polarization and boosts the specific capacity of the dry-sprayed electrode. When the current density increases from 0.5 C to 10 C, the reversible capacity retention of the dry-sprayed electrode is 74%, which is higher than that of the wet-coated electrode (56%). In addition, the powder resistivity of the dry-sprayed electrode decreases sharply by introducing two-dimension (2D) graphene nanoplate (GN) as the conductive agent, thus side effects have been effectively suppressed during the spraying process. As a result, the assembled LICs using the dry-sprayed LTO electrodes show superior energy density and excellent cycling performance, demonstrating this novel fabrication method has practical application prospects.

Self-supported graphene oxide encapsulated chalcopyrite electrode for high-performance Li-ion capacitor

The combination of lithium-ion batteries and supercapacitors makes lithium-ion capacitors (LICs) the ideal energy storage device for commercial applications. However, the high performance of LICs is restricted due to various shortcomings such as low electrode specific capacity and sluggish reaction kinetics. Additionally, the undesirable ‘polysulfide-diffusion’ effect in the cost-effective metal sulfide-based electrodes results in high capacity degradation. Therefore, developing novel strategies to surmount these drawbacks is of prime importance for the development of high-performance LICs. Herein, a novel composite material with the unique architecture of graphene oxide (GO) encapsulation on the chalcopyrite (CuFeS2) microspheres is fabricated as an anode for LIC. Compared to the traditional binder-based approach for electrode fabrication, the anode is fabricated using a ‘binder-free’ approach to enable the exposure of high-density electroactive sites. As a result, the fabrication of a ‘self-standing’ flexible electrode is obtained that finds numerous applications in wearable technology systems. Detailed electrochemical analysis reveals the enhanced reaction kinetics of the composite electrode along with the improved specific capacities and rate capabilities. The unique architecture of the GO encapsulation not only prevents the structural collapse of the chalcopyrite microspheres but also suppresses the polysulfide diffusion, resulting in higher cyclic stability. The role of such carbon encapsulation is studied in detail using experimental studies and is strongly supported by theoretical calculations based on density functional theory (DFT) for the first time. The calculated binding energy and charge transfer confirmed the improved interactive features of Li ions with the composite electrode in terms of enhanced binding energy and higher valence charge transfer. Additionally, the favorable binding energy of Li2S and Li2S4 polysulfides to the composite electrode than the pristine CFS electrode reflects restricted polysulfide diffusion, resulting in outstanding cyclic stability. The assembled LIC device based on the composite electrode displays a large energy density of 192.33 Wh/kg, a high power density of 14,280 W/kg, and excellent cyclic stability of >90 % for 10,000 cycles, outperforming most of the reported metal sulfide-based LICs.

Vanadium nitride nanoparticles embedded in carbon matrix with pseudocapacitive behavior for high performance lithium-ion capacitors

Vanadium nitride nanoparticles embedded in carbon matrix with pseudocapacitive behavior for high performance lithium-ion capacitors

SnO2/SnS2 heterostructure@ MXene framework as high performance anodes for hybrid lithium-ion capacitors

Among all kinds of energy storage devices, lithium-ion capacitors (LICs) emerged victorious because of their advantages of high energy densities and power densities. The main issue that limits the performance of LICs is the mismatch in reaction kinetics caused by the disparate energy storage mechanisms of the positive and negative materials. Herein, a Sn-based heterostructure@MXene anode material was synthesized to achieve excellent rate performance and to increase the lithium storage capacity, which enables a good match with the cathode. In the synthesized hybrid electrode, the heterostructure can regulate the charge transmission at interfaces and improve the kinetics of electron conduction and ion diffusion. Meanwhile, the highly conductive MXene can buffer the large volumetric change of SnS2/SnO2 nanoparticles, and synergically improve electrochemical properties of the hybrid electrode. The hybrid electrode exhibited remarkable rate performance and cycle stability, showing 619 mAh g−1 at 0.5 A g−1 after 200 cycles, which greatly reduced the kinetic gap with capacitor-type cathodes. The assembled LICs based on the SnS2/SnO2@MXene hybrid anode and nitrogen-doped activated carbon (N-AC) cathode offer a high power/energy density (maximum 11.25 kW kg−1 and 145.2 Wh kg−1) and a long cycling life (93.6% capacity retention after 2000 discharges/charges). This unique structure and the composition design provide a promising path for the fast kinetic LICs anode materials.

Anthracite-derived carbon-based electrode materials for high performance lithium ion capacitors

The capacity and electrochemical kinetics mismatches between cathode and anode are two major obstacles for lithium ion capacitors. In the work, graphene coating and electrochemical prelithiation are used to reinforce the properties of activated carbon and graphitized carbon as cathode and anode. The activated carbon with high specific surface area, and the graphitized carbon with porosity are prepared with anthracite as raw material, then both of them are modified with anthracite-derived graphene. As cathode, activated carbon coated with graphene shows a capacitance of 302 F g−1 with 75% capacitance retention after 10,000 cycles. The anode, graphitized carbon coated with graphene sheets delivers a capacity of 568.1 mAh g−1 at 0.1 A g−1 with 97% capacitance retention after 300 cycles. The LICs assembled with cathode and prelithiated anode show high energy and power densities, 315.1 Wh kg−1 at 300 W kg−1 and 133.3 Wh kg−1 at 15000 W kg−1, and superior cyclic stability, 78% capacity retention after 10,000 cycles. This work illustrates surface graphene coating and prelithiation to balance the capacity and electrochemical kinetics mismatches of electrodes in LICs and blaze an efficient route to convert anthracite to high performance electrodes for LICs and other energy storage systems.

Nitrogen-doped activated porous carbon for 4.5 V lithium-ion capacitor with high energy and power density

Lithium-ion capacitors (LICs) have become one of the most popular energy storage devices because of the combination of high energy densities and power densities. However, the kinetic imbalance of anode and cathode restricts the specific capacities and voltage windows of LICs. Herein, an in-situ nitrogen-doped activated porous carbon (ANMPC) material with high specific surface area (1894.9 m2/g) is proposed to act as both cathode and anode for the preparation of the 4.5 V “all carbon” LICs. The hierarchically porous ANMPC obtained by KOH activation and carbonization of polypyrrole (PPy) has plenty of mesopores created by surfactant (added during the PPy process) as well as micropores generated by KOH activation, thus can provide abundant active sites for ion intercalation and large area for electrostatic adsorption simultaneously, satisfying the critical requirements of high-performance anode and cathode, respectively. After coupling the pre-lithiated ANMPC anode and fresh ANMPC cathode, the complete LIC device delivers large energy density of 167.5 Wh/kg at a power density of 269.0 W/kg, and still remains 88.9 Wh/kg at an ultrahigh power density of 13,198.5 W/kg, exhibiting enormous potential for applications in high performance lithium-ion capacitors.

Reduced graphene oxide encapsulated MnO microspheres as an anode for high-rate lithium ion capacitors

Developing an anode material with high-rate Li+ intercalation and stable charge/discharge platform is important for achieving high performance lithium ion capacitors (LICs). Reduced graphene oxide (rGO)-encapsulated MnO microspheres (∼2 μm) are obtained by a simple process including solvothermal and calcination techniques. The material contains a large number of mesopores (∼2.8 nm diameter). The MnO/rGO has a favorable cycling stability (846 mAh g−1 at 0.1 A g−1 after 110 cycles) and an outstanding rate performance (207 mAh g−1 at 6.4 A g−1). Kinetic analysis reveals that a pseudocapacitive contribution plays a dominant role for the energy storage. The improvement in the pseudocapacitive behavior is ascribed to the fact that the uniform rGO coating on the MnO provides continuous pathways for electron transport, and the mesoporous structure provides numerous migration paths for Li-ions. Furthermore, MnO/rGO//activated carbon (AC) LICs have a high energy density of 98 Wh kg−1 at a relatively high power density of 10,350 W kg−1, and have a capacity retention of 71% after 5000 cycles at 1.6 A g−1. These outstanding results indicate that the enhanced Li+ intercalation of the anode offsets the kinetic imbalance between the two electrodes.

Porous FeP@C frameworks as anode materials for high performance lithium ion capacitors

Porous FeP@C networks are realized via a one-step calcination process, using ferric nitrate and phytic acid as the precursors of FeP along with thiourea and melamine as N, S precursors. Benefited from the cooperative hydrogen bonding of melamine and phytic acid, two dimensional (2D) frameworks embedded with FeP can be formed. This porous architecture largely favors the penetration of electrolyte and shortens the transfer length of Li+ ions. Moreover, the conductive carbon on FeP can significantly alleviate the volume change upon cycling and boost the electronic conductivity. Owing to their unique build, the FeP@C networks exhibit competitive rate performance and cycling stability with a large reversible capacity of 293.0 mAh g−1 at 4 A g−1 after 1000 cycles. Even at the ultrahigh current density of 6 A g−1, there is still a large reversible capacity of 218.3 mAh g−1. Therefore, the lithium ion capacitors (LICs) are devised by selecting the conductive FeP@C networks as anode materials and porous carbon as cathode materials. As expected, the LIC indicates a high energy density of 91.4 Wh kg−1 at the power density of 390 W kg−1.

Cobalt nanoparticles encapsulated by nitrogen-doped carbon framework as anode materials for high performance lithium-ion capacitors

In this work, we propose to prepare a nitrogen-doped nanocomposite ([email protected]) by one-step carbonization of the zeolite imidazole ester framework structure material (ZIF-67). Among them, the composite material uses porous carbon dodecahedron as the supporting framework, and the metal Co nanoparticles (12–15 nm) are encapsulated inside the carbon framework. The prepared nanocomposite demonstrates excellent electrochemical performance, and the electrode kinetic analysis shows extremely high pseudo-capacitance contribution and good cycle stability, almost no fluctuations during the cycle. Moreover, our assembled hybrid lithium-ion capacitor (LIC) has superb energy–density (125.28 Wh kg−1) and power-density (10 kW kg−1), and excellent cycle life (91.74% was retained after 1000 cycles), which is ascribed to the combined effect between the ideal component and multilayer structure of the prepared nanohybrid. This research work provides an effective solution for energy storage systems that take into account both high power and high energy density.

Material characteristics and electrochemical performance of lithium-ion capacitor with activated carbon cathode derived from sugarcane bagasse

Lithium-Ion Capacitor (LIC), a hybrid energy storage device, is believed to be an ideal option for energy storage device applications due to its properties with high specific energy and high specific power. In this study, LIC’s cathode material is made of activated carbon derived from sugarcane bagasse prepared by the carbonization process at 500OC for 60 minutes and activation process utilizing KOH as an activating agent at varying temperatures and varying ratios of carbon to KOH mass. This paper also compares the material characteristic and electrochemical performance. In this paper, full cells of LIC are fabricated using activated carbon as the cathode material and LTO as the anode material. Sugarcane bagasse activated carbons are characterized by Scanning Electron Microscopy (SEM) and Brunauer Emmett Teller (BET). The electrochemical performance of LIC is obtained from cyclic voltammetry (CV) and charge-discharge (CD). Sugarcane bagasse activated carbon (SBAC) produces a high specific surface area with values from 1095 m2/g to 3554 m2/g. The assembled LIC can produce a maximum specific capacitance of 31.94 F/g, the highest specific energy of 35.49 Wh/kg, and high specific power of 2954.36W/kg.

Improving the performance of lithium ion capacitor by stabilizing anode working potential using CoSe2 nanoparticles embedded nitrogen-doped hard carbon microspheres

Lithium-ion capacitors (LIC) have problems such as the imbalance of electrochemical kinetics between the battery-type anode and the capacitive cathode, and the large change in the working potential of the hard carbon anode during charge and discharge, which limit the improvement of electrochemical performance for LIC. To solve these problems, CoSe2 nanoparticles embedded nitrogen-doped hard carbon microspheres (NCS-CoSe2) are synthesized and used as the anode material of LIC. Electrochemical tests show that NCS-CoSe2 has a reversible specific capacity of as high as 500 mAh g−1 at a current density of 1 A g−1, which can effectively stabilize the working potential of the anode. At a high working voltage window of 2.2–4.5 V, the potential change of the NCS-CoSe2 anode is as low as 0.35 V, significantly smaller than that of the pure hard carbon (0.87 V). Regarding the electrode kinetics, the NCS-CoSe2 anode is matched with the active carbon cathode well. When the power density rises sharply from 335 W kg−1 to 6700 W kg−1, the energy density of NCS-CoSe2//AC LIC can attain 82 Wh kg−1 (56.9% of initial energy density).

S, O dual-doped porous carbon derived from activation of waste papers as electrodes for high performance lithium ion capacitors.

To circumvent the imbalances of electrochemical kinetics and charge-storage capacity between Li+ ion battery anodes and capacitive cathodes in lithium-ion capacitors (LICs), dual carbon based LICs are constructed and investigated extensively. Herein, S, O dual-doped 3D net-like porous carbon (S-NPC) is prepared using waste paper as the carbon source through a facile solvothermal treatment and chemical activation. Benefiting from the combination effect of the rich S,O-doping (about 2.1 at% for S, and 9.0 at% for O), high surface area (2262 m2 g−1) and interconnected porous network structure, the S-NPC-40 material exhibits excellent electrochemical performance as both cathode material and anode material for LICs. S, O doping not only increases the pseudocapacity but also improves the electronic conductivity, which is beneficial to reduce the mismatch between the two electrodes. The S-NPC-40//S-NPC-40 LIC delivers high energy densities of 176.1 and 77.8 W h kg−1 at power densities of 400 and 20 kW kg−1, respectively, as well as superior cycling stability with 82% capacitance retention after 20 000 cycles at 2 A g−1. This research provides an efficient method to convert waste paper to porous carbon electrode materials for high performance LIC devices.

Effect of fluoroethylene carbonate and vinylene carbonate additives on full-cell optimization of Li-ion capacitors

Lithium-ion capacitors (LICs) operate by two mechanisms, namely a double-layer mechanism based on a capacitor-like positive electrode and the intercalation mechanism of a battery-like negative electrode. Hence, well-designed reaction kinetics between the positive electrode and negative electrode are essential for optimizing LIC full-cell configurations. In this study, we investigated the influences of fluoroethylene carbonate (FEC) or vinylene carbonate (VC) as electrolyte additives on full-cell performance of LICs. We confirmed that the internal resistance of graphite increased with the use of FEC, which degraded the cyclability of the LIC full-cell. Conversely, LICs consisting of the VC additive had good cyclability over 4000 cycles owing to the solid electrolyte interphase (SEI) containing polymeric species. This detailed investigation into the function of SEI compounds derived from VC additives and their effect on cyclability will provide new insights into optimization of LIC full-cell configurations with appropriate electrolyte additives.

Sn–Ni Alloy Anode Pre-Doped in Vinylene Carbonate Containing Electrolyte for Lithium-Ion Capacitor

Lithium–ion capacitor (LIC), which is composed of non–Faraday reaction cathode used in electric double layer capacitor (EDLC), and Faraday reaction anode used in lithium–ion battery (LIB), is a promising energy storage device for electric vehicles, because LICs are ranked between LIBs and EDLCs for energy density and power density.1 LIC with Sn–Ni alloy anode is superior to that with a graphite anode in energy and power density. 2 For the purpose to improve its cycle durability to a practical level, the effect of vinylene carbonate (VC) which affects positively for LIBs, was investigated.Sn–Ni alloy anode was electrodeposited according to the previous report.3 The Sn–Ni alloy anode was pre-doped (pre-lithiated) by several charge–discharge cycles in an electrolyte with or without vinylene carbonate (VC). The LICs composed of an activated carbon cathode and the pre-doped Sn–Ni alloy anode were evaluated.The VC additive was revealed to affect positively during a pre-doping process and to affect negatively during charge–discharge cycling to the cycle performance of LIC. The difference for the additive effect was discussed by the potential changes and the morphology changes of the anode, revealing that VC formed a polymer-like SEI during the pre-doping process, suppressing deactivation of Sn caused by cracking growth and peeling-off during charge–discharge cycling. In contrast, VC was decomposed continuously during charge–discharge cycling with consuming pre-doped lithium. Thus, a strategy to use additives for alloying anode system was established. Finally, the excellent cycle durability (more than 10000 cycles with the capacity retention of 72.3%) of the LIC with high volumetric energy density of 38.9 Wh/L at 120 W/L was firstly demonstrated (Fig. 1). Acknowledgement This work is partially supported by Advanced Low Carbon Technology Research and Development Program of the Japan Science and Technology Agency (JST-ALCA, JPMJAL1008). References K. Naoi, S. Ishimoto, J. I. Miyamoto, and W. Naoi, Energy Environ. Sci., 5, 9363–9373 (2012).S. Ahn, Y. Nakamura, H. Nara, T. Momma, W. Sugimoto, and T. Osaka, J. Electrochem. Soc., 166, A3615–A3619 (2019).H. Mukaibo, T. Sumi, T. Yokoshima, T. Momma, and T. Osaka, Electrochem. Solid-State Lett., 6, A218 (2003). Figure 1

Precise Al2O3 Coating on LiNi0.5Co0.2Mn0.3O2 by Atomic Layer Deposition Restrains the Shuttle Effect of Transition Metals in Li-Ion Capacitors

Lithium ion capacitors (LICs), with their high power density and acceptable energy density have become a popular energy storage device on the market. Among various electrode materials of lithium ion batteries (LIBs), LiNi0.5Co0.2Mn0.3O2 (NCM), which has both high capacity and good cycle performance, has been widely used to improve the energy density of power devices. Unfortunately, the short cycle life and low power density of NCM have become new challenges for LICs. This work deeply analyzes the capacity failure mechanism of NCM in LICs during cycling, and finds that in the cycling process, the transition metal (TM) in NCM will dissolve and produce a shuttle effect, which eventually accumulates on the anode surface. Comfortingly, the precise Al2O3 coating on the NCM surface obtained by atomic layer deposition (ALD) successfully restrains the dissolution of TM in NCM during cycling, thus preventing the shuttle effect of TM. An additional benefit of the Al2O3 coating is to reduce internal stress changes of NCM secondary particles during long-time charging and discharging, thereby ensuring a close contact inside NCM particles after multiple cycles. As a result, the LICs assembled by the Al2O3 coated NCM composite cathode exhibit an excellent cycling capability and rate performance. This work paves a way for improving the electrochemical performance of LICs with the NCM cathode, and provides a reference for the further research on the performance attenuation mechanism of other composite electrodes in LICs.