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Problems of practical sodium-ion batteries.

A 180° faradaic shift is observed for a completely pre-lithiated Li4Ti5O12 anode when paired with an activated carbon cathode. The optimum range of pre-lithiation certainly enables attaining high energy and high power Li-ion capacitors.

The electrochemical performance of graphite recovered from 6H-pencil with the highest content of SiO

Development of robust electrode materials that can work for both Li- and Na-ion batteries received enormous interest in recent times. Especially, exploratory crystal growth offers much reward in re...

An immense effort has been put into developing high-performance electrodes to commercialize sodium-ion batteries, but research on developing an efficient electrolyte is lacking. This study aims to find the best carbonate-based electrolyte systems by incorporating the existing ideas reported in this field. The sodium superionic conductor (NASICON) type Na3V2(PO4)2F3-C (NVPF-C) was chosen as a cathode, and its compatibility with four different carbonate-based electrolyte solutions was studied in the half-cell assembly. Additionally, full-cell assembly with hard carbon as an anode is also explored. Binary and ternary combinations of the solvents ethylene carbonate, propylene carbonate, and dimethyl carbonate were employed with and without fluoroethylene carbonate as an additive. A systematic study was performed, including the in-situ impedance technique, and to determine the compatibility. Detailed galvanostatic studies for NVPF-C based half-cells, as well as hard carbon/NVPF-C full-cells, are performed, which shows that 1 M NaClO4 in propylene carbonate:dimethyl carbonate + fluoroethylene carbonate is a better electrolyte composition for this assembly. Subsequently, a temperature study was carried out on this electrolyte to test its performance.

Electrochemical energy-storage technologies remain the only key to solve the increasing demands of global energy supply, zero-emission transportation, and grid storage in a greener way. Accordingly, novel strategies and the new promising designs of electrodes attempt to conquer the high energy density of supercapacitors without decreasing their power density and cycle life. In supercapacitors, asymmetric supercapacitors outshine the symmetric supercapacitors ( 2.0 V) in a safer way using aqueous electrolytes. Especially, emerging high energy supercapacitors perfected by suitable low cost-electrode materials are now the crown of energy storage research. Employing battery type Ni(OH)2 as a positive electrode has become a promising approach to building next-generation high energy supercapacitors besides its abundance, cost efficiency, environment friendliness, and high theoretical capacity. This review exclusively elaborates the unnoticed vision into the design, fabrication, mechanism, and investigation of such fascinating Ni(OH)2 based supercapacitors in an asymmetric fashion. Further, this review eventually mitigates the issues associated with the Ni(OH)2 component toward the goal of building next-generation supercapacitors for a sustainable environment.

The abundance of sodium and the absence of costly transition metals in electrodes are the significant strongholds of dual carbon sodium-ion capacitors (DC-NICs) due to which they are cheaper and readily available compared to other prominent energy storage devices. A perfect amalgamation of energy and power density is the aim of DC-NICs, which is achieved by combining carbon-based battery type and capacitor type electrodes and using a suitable electrolyte. An optimum combination of surface area, the volume of pores, and ordering of the structure applied to both the anode and the cathode enable the efficient fusion of energy density and power density. Battery-type electrodes are mainly ordered carbon structures (graphite, hard carbon, or layered structures), which promote the faradaic mechanism-based energy storage that imparts high energy density. Structural modification aimed towards providing a higher number of pores and surface area has improved the high rate performance and power density of such structures. A majority of the capacitor-type electrodes are fabricated with a very large surface area (activated carbon or highly porous structures) to bolster the power density, which is promoted via the surface charge-storage process. Through material engineering including defects and functional groups, additional charge storage sites are created that can improve the energy density. DC-NICs fabricated from biomass precursors are promising and exhibit performance on par with that of lithium-ion batteries. High power and energy densities make DC-NICs a suitable candidate for electric vehicle applications. Though DC-NIC is a novel concept, the progress within a short time is immense, with the capability to provide clean, green, and cost-effective energy. Reported works have been studied and factors that played a crucial role in improving the performances have been highlighted. Some parameters that govern the performance of DC-NICs and can help future research works have been discussed.

Spent lithium-ion batteries (LIBs) offer immense potential in the form of resources such as Li, transition metals (Co, Ni, and Mn), graphite, and Cu, which can be recovered through suitable recycling procedures. The Cu-current collector is recovered from spent LIBs and converted as a copper oxide (CuO) anode for Na-ion batteries. The performance of CuO is evaluated with carboxymethyl cellulose (CMC) (CuO-C), and polyvinylidene fluoride (PVdF) (CuO-P) binders in CuO half-cell and CuO/carbon-coated Na

High-performance Na-ion capacitor (NIC) was constructed with graphite recovered from spent Li-ion batteries (LIBs) as battery-type negative electrode and high-surface-area activated carbon as a supercapacitor component. Unlike Li-insertion into graphite, Na-insertion into graphite is extremely limited; hence, a "solvent-co-intercalation" mechanism was proposed for high reversibility using ether family solvents. First, the Na-insertion properties were assessed in the half-cell assembly with 0.5 m NaPF6 in tetraethylene glycol dimethyl ether as an electrolyte solution and compared with the commercial graphite. The NIC comprised pre-sodiated graphite as a negative electrode and commercial activated carbon as a cathode. This fascinating NIC configuration displayed the maximum energy density of 59.93 Wh kg-1 with exceptional cyclability of 5000 cycles at ambient temperature with approximately 98 % retention. Interestingly, the electrode aging process in the presence of electrolyte resulted in approximately 19 % higher energy density than the routine electrode heat treatment. Further, the electrochemical activity of the NIC at various temperatures was studied, and it was found that the graphite recovered from spent LIBs could be effectively reused towards the construction of high-performance charge storage devices with exceptional performance.

We report the excellent charge storage performance of high-energy Li-ion capacitors (LIC) fabricated from the mesoporous Co3O4 nanosheets as the conversion-type battery component and Jack fruit (Artocarpus heterophyllus) derived activated carbon as a supercapacitor electrode, especially at high temperatures (50 and 40 °C). Prior to the fabrication, the electrochemical prelithiation strategy was applied to Co3O4 to alleviate the irreversibility and enrich the Li-ions for electrochemical reactions (Co0 + Li2O). The LIC delivered a maximum energy density of ∼118 Wh kg-1 at a high temperature of 50 °C. The significant difference is observed at a high rate of 2.6 kW kg-1 at 50 °C with excellent cycle stability up to 3000 cycles, with a retention of ∼87% compared with the LIC cycled at room temperature (∼74%). The magnificent electrochemical performance clearly demonstrates that the mesoporous structure and residual carbon synergistically facilitated the Li+/electron transport and hinder undesirable side reactions with electrolytes to realize high-energy density at high temperatures.

Surface modification is one of the impressive and widely used technique to improve the electrochemical performance of sodium-ion batteries by modifying the electrode-electrolyte interface. Herein, we used the atomic layer deposition (ALD) to modify the surface of P2-Na0.5Mn0.5Co0.5O2 by sub-monolayer Al2O3 coating on the prefabricated electrodes. Phase purity is confirmed using various structural and morphological studies. The pristine electrode delivered an initial discharge capacity of 154 mAh g−1 at 0.5C, and inferior rate performance of 23 mAh g−1 at 40C rate. On the other hand, the interfacial modified cathode with 5 cycles of ALD coating delivers a high capacity of 174 and 45 mAh g−1 at 0.5C and 40C rate, respectively. The Co2+/3+ redox couple is utilized for the faradaic process with high reversibility along with suppressed P2-O2 phase transition. The presence of the Al2O3 layer acts as an artificial cathode electrolyte interface by suppressing the electrolyte oxidation at higher cutoff potentials. This is clearly validated by the reduced charge transfer resistance of surface modified electrodes after cycling at various current rates. Even at an elevated temperature condition (50 °C), interfacial layer significantly improves the safety of the cell and ensures the stability of the cathode.

Developing novel cathode materials with a high energy density and long cycling stability is necessary for Na-ion batteries and Na-ion hybrid capacitors (NICs). Despite their high energy density, structural flexibility, and ease of synthesis, P-type Na layered oxides cannot be utilized in energy-storage applications owing to their severe capacity fading. In this regard, we report a novel composite layered-tunnel Na

Revitalized attention in cost-effective vanadium pentoxide (V2O5) to ensure high-performance next-generation lithium-ion batteries (LIBs) via an easy synthesis protocol, with increased capacity, and two-dimensional (2D) Li-ion transportation pathways, results in a higher power capability than for one-dimensional (1D) migration pathway cathodes, such as LiFePO4. V2O5 has pride of place as a maximum reversibility cathode amongst other cathode materials and overcomes the obstacle of high energy density for LIBs by the evolution of different phases according to the degree of lithium intercalation. The four phase transformations of α ↔ e, e ↔ δ, δ ↔ γ, and γ ↔ ω, according to the Li-insertion numbers, can have different equilibrium potentials vs. Li, which is worth mentioning. Furthermore, this 2D-layered structure attains the theoretical capacity of 147 mA h g−1 in the limited 1 mol Li-insertion, which is comparable to the performance of LiFePO4 in terms of both working potential and capacity. Excess Li-intercalation leads either to large polarization or induces structural destruction, which makes this fascinating cathode unfit for potential applications. Although there are a few review articles available on V2O5-based cathodes, no reports exist on the fabrication of full-cells using this cathode. This review pays particular attention to the recent improvements in V2O5-based LIBs paired with different kinds of anodes, namely insertion, conversion, and alloying types. Challenges in the development of V2O5-based LIBs that would help to achieve advanced batteries in future, especially limiting 1 mol Li-ion intercalation to enable a promising candidate, are also discussed.

Graphite, an ordered layered structure, has been the dominant choice as a stable electrode material since the commercialization of lithium-ion batteries (LIBs), which could bring about a significant increase in demand for the material owing to its usage in forthcoming graphite-based energy storage devices. In this work, we propose an efficient route to reutilize recovered graphite (RG) from spent LIBs as an anode material for the fabrication of lithium-ion capacitors (LICs) after the required treatment. It was found that RG displayed a first excellent performance in a half-cell configuration, which further encouraged us to assemble a full cell using activated carbon as the cathode. Prior to the fabrication of the LIC, the RG was pre-lithiated (LiC6) to form a graphite intercalation compound to supply Li ions. The resultant dual-carbon LIC in an aprotic organic solvent delivered a maximum energy density of 185.54 W h kg−1 at a power density of 0.319 kW kg−1 at ambient conditions. Furthermore, different temperature performance analysis revealed that the assembled LIC presented a good cycling performance for a continuous 2000 cycles with ∼75% capacity retention at 10 °C and 25 °C. The developed dual carbon-based LIC using recovered RG from spent LIBs offers several promising features, such as low cost and good applicability in a wide range of temperature operations as well as providing a real solution to recycle the upcoming massive quantity of spent LIBs generated by different electronic appliances.

Summary Antimony-based materials are promising anode candidates for sodium-ion batteries (NIBs) due to their high theoretical capacity of 660 mAh g–1 (Na3Sb). In fact, antimony-based alloying and conversion-alloying electrodes exhibit high capacity and cycling stability, with newly developed strategies to overcome the common problem of volume expansion, all leading to renewed interest in antimony-based NIB materials. In this review, we discuss the performance of antimony-based materials for energy storage and conversion devices such as NIBs, Na-ion fuel cells, sea-water batteries, and Na-air batteries. This review also tackles common issues in NIBs that employ antimony-based materials (e.g., Sb–carbon composite and Sb2X3 (X – O, and S), as well as several strategies that can be adopted to address these limitations.

In this study, we explored the feasibility of using electrochemically generated γ-Lix V2 O5 as an insertion-type anode in the lithium-ion capacitor (LIC) with activated carbon (AC) as a cathode. Along with the native form of V2 O5 , their carbon composites are also used as the electrode material which is prepared by high-energy ball milling. The electrochemical pre-lithiation strategy is used to generate the desired γ-phase of V2 O5 (γ-Lix V2 O5 ). Under the optimized mass loading conditions, the LICs are assembled with γ-Lix V2 O5 as anode and AC as a cathode in the organic medium. Among the different LICs fabricated, AC/γ-Lix V2 O5 -BM50 configuration delivered an energy density of 33.91 Wh kg-1 @ 0.22 kW kg-1 with excellent capacity retention characteristics. However, a dramatic increase in energy density (43.98 Wh kg-1 @0.28 kW kg-1 ) is noted after the electrolyte modification with fluoroethylene carbonate. The high temperature performance of the assembled LIC is also studied and found that γ-Lix V2 O5 phase can be used as a potential battery-type component to construct high-performance hybrid charge storage devices.

Because of the demand for sustainable energy storage devices, investigating high energy density and cost-effective electrodes for flexible supercapacitors (SCs) is essential; however, the emergence...

High power capability of the hybrid charge storage device Na-ion capacitor (NIC) is fabricated using battery type TiS2 as an insertion host with the double layer forming activated carbon (AC) as supercapacitor component. Earlier, it is presumed that Na/TiS2 system is considered as impractical energy storage system. TiS2 single crystals are synthesized and exhibit the reversible insertion of ~0.62 mol. Na. AC/TiS2 assembly is delivering the maximum energy density of ~38 Wh kg−1. One of the important aspects of this NIC is high power capability, which outperformed its analogue Li-ion capacitor fabricated under similar circumstances. Ministry of Education (MOE) Nanyang Technological University National Research Foundation (NRF) Accepted version This work was financially supported by NTU-HUJ Create Phase II which is a joint research programme between the Hebrew University of Jerusalem (HUJ, Israel) and Nanyang Technological University (NTU, Singapore) with CREATE (Campus for Research Excellence and Technological Enterprise) funding from National Research Foundation of Singapore (NRF, Singapore). Also, thank the financial support from the Ministry of Education - Singapore (MOE TIER 2 funding MOE2015-T2-1-046). VA thanks the financial support from the Science & Engineering Research Board (SERB), a statutory body of the Department of Science &Technology, Govt. of India through Ramanujan Fellowship (SB/S2/RJN-088/2016).

Biomass-derived carbon materials have received special attention as efficient, low-cost, active materials for charge-storage devices, regardless of the power system, such as supercapacitors and rechargeable batteries. In this Minireview, we discuss the influence of biomass-derived carbonaceous materials as positive or negative electrodes (or both) in high-energy hybrid lithium-ion configurations with an organic electrolyte. In such hybrid configurations, the electrochemical activity is completely different to conventional electrical double-layer capacitors; that is, one of the electrodes undergoes a Faradaic reaction, whilst the counter electrode undergoes a non-Faradaic reaction, to achieve high energy density. The use of a variety of biomass precursors with different properties, such as surface functionality, the presence of inherent heteroatoms, tailored meso-/microporosity, high specific surface area, various degrees of crystallization, calcination temperature, and atmosphere, are described in detail. Sodium-ion capacitors are also discussed, because they are an important alternative to lithium-ion capacitors, owing to the low abundance and high cost of lithium. The electrochemical performance of carbonaceous electrodes in supercapacitors and rechargeable batteries are not discussed.

Herein, we report the facile synthesis of carbon hollow spheres (CHS) and reduced graphene oxide (rGO) from separators and graphite recovered from a spent lithium-ion battery (LIB), respectively, towards a “Waste-to-Wealth” approach. Subsequently, both CHS and rGO were employed to explore the gas storage capabilities for storing various gases such as N2, H2, and CO2. For the first time, a facile one-step carbonization process was employed to concoct CHS from the recovered polymer separators without the use of a template. Similarly, the synthesis of rGO was undertaken entirely via the mended graphite and using the outer metallic Al cases as a reducing agent. The specific surface area and total pore volume of rGO and CHS were estimated to be 374 & 402 m2 g−1 and 0.16 & 0.30 cm3 g−1, respectively. Moreover, the H2 uptake at 15 bar and 77 K was found to be 1.78 wt% for rGO and 1.22 wt% for CHS. Interestingly, the acquired rGO from the waste constituents displays a high CO2 uptake of 12 wt% and 33 wt% can be stored in the CHS at 40 bar and 298 K. This study affords the prospect of alternate/efficient gas storage materials by recycling spent LIB in an economically and environmentally friendly approach.