Reversible Batteries Research Articles

High‐Voltage Single‐Ion Covalent Organic Framework Electrolytes Enabled by Nitrile Migration Ladders for Lithium Metal Batteries

AbstractThe poor electrochemical stability window and low ionic conductivity in solid‐state electrolytes hinder the development of safe, high‐voltage, and energy‐dense lithium metal batteries. Herein, taking advantage of the unique electronic effect of nitrile groups, we designed a novel azanide‐based single‐ion covalent organic framework (CN−iCOF) structure that possesses effective Li+ transport and high‐voltage stability in lithium metal batteries. Density functional theory (DFT) calculations and molecular dynamics (MD) revealed that electron‐withdrawing nitrile groups not only resulted in an ultralow HOMO energy orbital but also enhanced Li+ dissociation through charge delocalization, leading to a high tLi+ of 0.93 and remarkable oxidative stability up to 5.6 V (vs. Li+/Li) simultaneously. Moreover, cyanation leveraging Strecker reaction transformed reversible imine‐linkage to a stable sp3‐carbon‐containing azanide anion, which facilitated contorted alignment of transport “ladders” along the one‐dimensional anionic channels and the ionic conductivity could reach 1.33×10−5 S cm−1 at ambient temperature without any additives. As a result, CN−iCOF allowed operation of solid‐state lithium metal batteries with high‐voltage cathodes such as LiNi0.8Mn0.1Co0.1O2 (NCM811), demonstrating stable lithium deposition up to 1,100 h and reversible battery cycling at ambient temperature up to 4.5 V, shedding light on the importance of discovering new functionality for forthcoming high‐performance batteries.

Hollow Core-Shelled Na4Fe2.4Ni0.6(PO4)2P2O7 with Tiny-Void Space Capable Fast-Charge and Low-Temperature Sodium Storage.

Iron-based mixed polyanion phosphate Na4Fe3(PO4)2P2O7 (NFPP) is recognized as a promising cathode for Sodium-ion Batteries (SIBs) due to its low cost and environmental friendliness. However, its inherent low conductivity and sluggish Na+ diffusion limit fast charge and low-temperature sodium storage. This study pioneers a scalable synthesis of hollow core-shelled Na4Fe2.4Ni0.6(PO4)2P2O7 with tiny-void space (THoCS-0.6Ni) via a one-step spray-drying combined with calcination process due to the different viscosity, coordination ability, molar ratios, and shrinkage rates between citric acid and polyvinylpyrrolidone. This unique structure with interconnected carbon networks ensures rapid electron transport and fast Na+ diffusion, as well as efficient space utilization for relieving volume expansion. Incorporating regulation of lattice structure by doping Ni heteroatom to effectively improve intrinsic electron conductivity and optimize Na+ diffusion path and energy barrier, which achieves fast charge and low-temperature sodium storage. As a result, THoCS-0.6Ni exhibits superior rate capability (86.4 mAh g-1 at 25 C). Notably, THoCS-0.6Ni demonstrates exceptional cycling stability at -20 °C with a capacity of 43.6 mAh g-1 after 2500 cycles at 5 C. This work provides a universal strategy to design the hollow core-shelled structure with tiny-void space cathode materials for reversible batteries with fast-charge and low-temperature Na-storage features.

Hollow Core‐Shelled Na4Fe2.4Ni0.6(PO4)2P2O7 with Tiny‐Void Space Capable Fast‐Charge and Low‐Temperature Sodium Storage

AbstractIron‐based mixed polyanion phosphate Na4Fe3(PO4)2P2O7 (NFPP) is recognized as a promising cathode for Sodium‐ion Batteries (SIBs) due to its low cost and environmental friendliness. However, its inherent low conductivity and sluggish Na+ diffusion limit fast charge and low‐temperature sodium storage. This study pioneers a scalable synthesis of hollow core–shelled Na4Fe2.4Ni0.6(PO4)2P2O7 with tiny‐void space (THoCS‐0.6Ni) via a one‐step spray‐drying combined with calcination process due to the different viscosity, coordination ability, molar ratios, and shrinkage rates between citric acid and polyvinylpyrrolidone. This unique structure with interconnected carbon networks ensures rapid electron transport and fast Na+ diffusion, as well as efficient space utilization for relieving volume expansion. Incorporating regulation of lattice structure by doping Ni heteroatom to effectively improve intrinsic electron conductivity and optimize Na+ diffusion path and energy barrier, which achieves fast charge and low‐temperature sodium storage. As a result, THoCS‐0.6Ni exhibits superior rate capability (86.4 mAh g−1 at 25 C). Notably, THoCS‐0.6Ni demonstrates exceptional cycling stability at −20 °C with a capacity of 43.6 mAh g−1 after 2500 cycles at 5 C. This work provides a universal strategy to design the hollow core–shelled structure with tiny‐void space cathode materials for reversible batteries with fast‐charge and low‐temperature Na‐storage features.

High-Voltage Single-Ion Covalent Organic Framework Electrolytes Enabled by Nitrile Migration Ladders for Lithium Metal Batteries.

The poor electrochemical stability window and low ionic conductivity in solid-state electrolytes hinder the development of safe, high-voltage, and energy-dense lithium metal batteries. Herein, taking advantage of the unique electronic effect of nitrile groups, we designed a novel azanide-based single-ion covalent organic framework (CN-iCOF) structure that possesses effective Li+ transport and high-voltage stability in lithium metal batteries. Density functional theory (DFT) calculations and molecular dynamics (MD) revealed that electron-withdrawing nitrile groups not only resulted in an ultralow HOMO energy orbital but also enhanced Li+ dissociation through charge delocalization, leading to a high tLi+ of 0.93 and remarkable oxidative stability up to 5.6 V (vs. Li+/Li) simultaneously. Moreover, cyanation leveraging Strecker reaction transformed reversible imine-linkage to a stable sp3-carbon-containing azanide anion, which facilitated contorted alignment of transport "ladders" along the one-dimensional anionic channels and the ionic conductivity could reach 1.33×10-5 S cm-1 at ambient temperature without any additives. As a result, CN-iCOF allowed operation of solid-state lithium metal batteries with high-voltage cathodes such as LiNi0.8Mn0.1Co0.1O2 (NCM811), demonstrating stable lithium deposition up to 1,100 h and reversible battery cycling at ambient temperature up to 4.5 V, shedding light on the importance of discovering new functionality for forthcoming high-performance batteries.

Cement/Sulfur for Lithium-Sulfur Cells.

Lithium-sulfur batteries represent a promising class of next-generation rechargeable energy storage technologies, primarily because of their high-capacity sulfur cathode, reversible battery chemistry, low toxicity, and cost-effectiveness. However, they lack a tailored cell material and configuration for enhancing their high electrochemical utilization and stability. This study introduces a cross-disciplinary concept involving cost-efficient cement and sulfur to prepare a cement/sulfur energy storage material. Although cement has low conductivity and porosity, our findings demonstrate that its robust polysulfide adsorption capability is beneficial in the design of a cathode composite. The cathode composite attains enhanced cell fabrication parameters, featuring a high sulfur content and loading of 80 wt% and 6.4 mg cm-2, respectively. The resulting cell with the cement/sulfur cathode composite exhibits high active-material retention and utilization, resulting in a high charge storage capacity of 1189 mA∙h g-1, high rate performance across C/20 to C/3 rates, and an extended lifespan of 200 cycles. These attributes contribute to excellent cell performance values, demonstrating areal capacities ranging from 4.59 to 7.61 mA∙h cm-2, an energy density spanning 9.63 to 15.98 mW∙h cm-2, and gravimetric capacities between 573 and 951 mA∙h g-1 per electrode. Therefore, this study pioneers a new approach in lithium-sulfur battery research, opting for a nonporous material with robust polysulfide adsorption capabilities, namely cement. It effectively showcases the potential of the resulting cement/sulfur cathode composite to enhance fabrication feasibility, cell fabrication parameters, and cell performance values.

Design Principles for Heterointerfacial Alloying Kinetics at Metallic Anodes in Rechargeable Batteries

How surface chemistry influences reactions occurring thereupon has been a long-standing question of broad scientific and technological interest. Here we consider the relation between the surface chemistry at such interfaces and the reversibility of electrochemical transformations at rechargeable battery electrodes. Using Zn as a model system, we report that a moderate strength of chemical interaction between the deposit and the substrate—neither too weak nor too strong—enables highest reversibility and stability of the plating/stripping redox processes. Focused-ion-beam and electron microscopy were used to directly probe the morphology, chemistry and crystallography of the heterointerfaces of distinct natures. Analogous to the empirical Sabatier principle for chemical heterogeneous catalysis, our finding arises from the confluence of competing interfacial processes. Using full batteries with stringent N:P ratios, we show that such knowledge provides a powerful tool for designing key materials in highly reversible battery systems based on earth-abundant, low-cost metals such as Zn and Na.Reference: Zheng, Jingxu, et al. "Design principles for heterointerfacial alloying kinetics at metallic anodes in rechargeable batteries." Science Advances 8.44 (2022): eabq6321.

Ultrahigh-Speed Aqueous Copper Electrodes Stabilized by Phosphorylated Interphase.

High-energy metal anodes for large-scale reversible batteries with inexpensive and nonflammable aqueous electrolytes promise the capability of supporting higher current density, satisfactory lifetime, nontoxicity, and low-cost commercial manufacturing, yet remain out of reach due to the lack of reliable electrode-electrolyte interphase engineering. Herein, in situ formed robust interphase on copper metal electrodes (CMEs) induced by a trace amount of potassium dihydrogen phosphate (0.05m in 1m CuSO4 -H2 O electrolyte) to fulfill all aforementioned requirements is demonstrated. Impressively, an unprecedented ultrahigh-speed copper plating/stripping capability is achieved at 100mA cm-2 for over 12000 cycles, corresponding to an accumulative areal capacity up to tens of times higher than previously reported CMEs. The use of solid-electrolyte interface-protection strategy brings at least an order of magnitude improvement in cycling stability for symmetric cells (Cu||Cu, 2800h) and full batteries with CMEs using either sulfur cathodes (S||Cu, 1000 cycles without capacity decay) or zinc anodes (Cu||Zn with all-metal electrodes, discharge voltage ≈1.02V). The comprehensive analysis reveals that the hydrophilic phosphate-rich interphase nanostructures homogenize copper-ion deposition and suppress nucleation overpotential, enabling dendrite-free CMEs with sustainability and ability to tolerate unusual-high power densities. The findings represent anelegantforerunnertoward the promising goal of metal electrode applications.

Additive-free Electrophoretic-deposited Ti3AlC2 MAX phase Li-ion battery anode

• We demonstrated its excellent cycling stability and reversible recovery for MAX anode. • Delamination process activates both faradic and non-faradaic processes. • Pseudocapacitive redox reactions led to reversible battery charging/discharging cycles. M n+1 AX n (MAX, n=1, 2, 3…) is the precursor of Mxene, which is two-dimensional layered transition metal carbides and nitrides. The two-dimensional Mxene layers are fabricated through selective etching of element “A”. To probe the intrinsic electrochemical properties of Ti 3 AlC 2 MAX phase as Li-ion battery anode, we fabricated an additive-free electrophoretically-deposited MAX phase anode electrode. As demonstrated in this report, the MAX phase is highly reversible during charging and discharging cycles, as a result of pseudocapacitive redox reactions caused by delamination of Ti 3 AlC 2 nanolayer aggregates into nanosheets during delithiation. In the present study, we demonstrate excellent cycling reversibility for a Ti 3 AlC 2 MAX phase electrode electrophoretically deposited without additives with a specific capacity of ∼120 mAh/g after cycles up to 10 C-rate.

Design principles for heterointerfacial alloying kinetics at metallic anodes in rechargeable batteries.

How surface chemistry influences reactions occurring thereupon has been a long-standing question of broad scientific and technological interest. Here, we consider the relation between the surface chemistry at interfaces and the reversibility of electrochemical transformations at rechargeable battery electrodes. Using Zn as a model system, we report that a moderate strength of chemical interaction between the deposit and the substrate-neither too weak nor too strong-enables highest reversibility and stability of the plating/stripping redox processes. Focused ion beam and electron microscopy were used to directly probe the morphology, chemistry, and crystallography of heterointerfaces of distinct natures. Analogous to the empirical Sabatier principle for chemical heterogeneous catalysis, our findings arise from competing interfacial processes. Using full batteries with stringent negative electrode-to-positive electrode capacity (N:P) ratios, we show that such knowledge provides a powerful tool for designing key materials in highly reversible battery systems based on Earth-abundant, low-cost metals such as Zn and Na.

Secondary FeF2-Li Batteries in Ionic Liquid Electrolytes

Conventional intercalation Li-ion batteries are physico-chemically limited in their energy density and exhibit a restricted temperature operation range. To further increase energy density limit and enable reversible battery cycling at elevated temperatures, the exploitation of new cell chemistry is required. Conversion-type transition metal fluorides (TMFs) can store multiple Li-ions per metal center and thus increase the theoretical energy density by 200% to 300% compared to intercalation compounds. [1] Ionic liquids (ILs) are liquid salts (below 100°C) with improved thermal stability due to the ionic nature of its constituents, little to no flammability, and a low vapor pressure. Combining a TMF cathode with an IL electrolyte and a metallic lithium anode can provide an energy-dense, safe energy storage alternative with a broader operating temperature range and additional versatility for applications in the military, oil, and aerospace sector. [2]In my talk, I will discuss our progress on the development and characterisation of a secondary FeF2-IL-Li-metal battery. We studied the impact of active material morphology and carbon-composite preparation techniques on the electronic conductivity and electrochemical performance in a bis(fluorosulfonyl)imide based IL electrolyte. In addition, we investigated different IL formulations for their applicability with TMFs and Li-metal. Both the cathode and anode electrolyte interphases were studied at different temperatures and their role in a full cell setup is elucidated.[1] Olbrich, L. F., Xiao, A. W. & Pasta, M. Conversion-type fluoride cathodes: Current state of the art. Current Opinion in Electrochemistry 30, 100779 (2021).[2] Lin, X., Salari, M., Arava, L. M. R., Ajayan, P. M. & Grinstaff, M. W. High temperature electrical energy storage: Advances, challenges, and frontiers. Chemical Society Reviews 45, 5848–5887 (2016). Figure 1

Efficient Modulation of Electron Pathways by Constructing a MnO2-x@CeO2 Interface toward Advanced Lithium-Oxygen Batteries.

A major challenge for Li-O2 batteries is to facilely achieve the formation and decomposition of the discharge product Li2O2, and the development of an active and synergistic cathode is of great significance to efficiently accelerate its formation/decomposition kinetics. Herein, a novel strategy is presented by constructing a MnO2-x@CeO2 heterostructure on the porous carbon matrix. When it was used as a cathode for Li-O2 batteries, excellent electrochemical performances, including low overpotential, large discharge capacity, and superior cycling stability were obtained. Series theoretical calculations were conducted to reveal the mechanism for the reversible battery reactions and explain how Li2O2 interacts with the MnO2-x@CeO2 interface. Apart from the electronic ladders formed between MnO2-x 3d and CeO2 4f orbitals, which can act as a highly efficient "electron transfer expressway", the specific adsorption of MnO2-x and CeO2 with Li2O2 molecules contributes to the enhanced anchoring force of Li2O2 and delocalization of the electron cloud on the Li-O bond. Thanks to the constructed heterostructure and synergistic effect, filmlike Li2O2 can be formed through a surface pathway, and when charging, it accelerates the separation of electrons and Li+ in Li2O2, thus achieving fast redox kinetics and low overpotential.

Designing and Demystifying the Lithium Metal Interface toward Highly Reversible Batteries.

Reversible lithium (Li) plating/stripping is essential for building practical high-energy-density batteries based on Li metal chemistry, which unfortunately remains a severe challenge. In this contribution, it is demonstrated that through the rational regulation of strong Li+ -anion coordination structures in a highly compatible low-polarity solvent, 2-methyl tetrahydrofuran, the Li plating/stripping assisted by a nucleation modulation procedure delivers a remarkably high average Coulombic efficiency under rather demanding conditions (99.7% and 99.5% under 1.0mAcm-2 , 3.0mAh cm-2 and 3.0mAcm-2 , 3.0mAh cm-2 , respectively). The exceedingly reversible cycling obtained herein is fundamentally correlated with the flattened Li deposition and minimized solid electrolyte interphase (SEI) generation/reconstruction in the customized condition, which notably restrains the growth rates of both dead Li0 (0.0120mAh per cycle) and SEI-Li+ (0.0191mAh per cycle) during consecutive cycles. Benefiting from the efficient Li plating/stripping manner, the assembled anode-free Cu|LiFePO4 (2.7mAh cm-2 ) coin and pouch cells exhibit impressive capacity retention of 43.8% and 41.6% after 150 cycles, respectively, albeit with no optimization on the test conditions. This work provides guidelines into the targeted interfacial design of high-efficiency working Li anodes, aiming to pave the way for the practical deployment of high-energy-density Li metal batteries.

Nanostructured conductive polymer shield for highly reversible dendrite-free zinc metal anode

Zinc ion batteries (ZIBs) are promising candidates for application in next-generation energy storages because of their high capacity, low cost, and safety. However, structural issues such as irregular Zn growth, volume change, and electrochemical issues (side reactions and byproducts) hinder their practical application. Herein, we present an innovative method to develop a nanostructured conductive polymer shield for a Zn anode, which leads to an efficient and reversible ZIBs. The direct and spontaneous deposition of nanostructured conductive polymer on a Zn surface plays vital role of mechanical and electrochemical shield for Zn anode. The 3D-PPy@Zn anodes display high symmetric cycling stability for up to 1500 h at 1 mA cm−2, and the full cell assembled with a MnO2 cathode exhibits highly reversible battery performance.

Unraveling the mechanical origin of stable solid electrolyte interphase

Summary The capability of a solid electrolyte interphase (SEI) in accommodating deformation is critical to the electrode integrity. However, the nanoscale thickness and environmental sensitivity of SEI make it challenging to characterize multiple mechanical parameters and identify an appropriate predictor for such capability. Here, we develop a feasible atomic force microscopy (AFM)-based nanoindentation test that circumvents the interference of the anode substrate and allows accurate probing of Young's modulus and elastic strain limit of SEI. The "maximum elastic deformation energy" (U) that an SEI can absorb is proposed to predict the stability of the SEI, as successfully demonstrated in Li/K metal anodes. We show that another asset of U is to provide a rapid and effective means to screen proper electrolytes for the stabilization of Sn and Sb microparticle anodes through building high-U SEIs. Overall, this new indicator, U, offers future directions toward rational design of robust SEIs for advanced anodes.

An Efficient and Reversible Battery Anode Electrode Derived from a Lead-Based Metal–Organic Framework

Metal–organic frameworks (MOFs) are porous crystalline materials with tailorable structural versatility that were recently considered as one of the most promising alternative anode materials for lithium-ion batteries. Herein, we have synthesized lead-based MOFs (Pb-1,3,5-benzenetricarboxylate, Pb-BTC), which had a high efficiency and reversibe lithium storage for anode material in lithium-ion batteries. The Pb-BTC based battery delivers highly reversible lithium storage capacities of 625 and 450 mA h g–1 at current densities of 0.1 and 0.5 A g–1, respectively, and can maintain its performance up to 150 charging/discharging cycles. The ex situ X-ray photoelectron spectroscopic studies on the electrode materials at different charging/discharging states and cyclic intervals reveal that the Li+ insertion, conversion, and alloying mechanism play central roles on improving the lithium storage capability. The DFT simulation reveals that the Pb sites in MOFs absorb Li atoms efficiently that support the high storage capacity. The electrochemical performance of Pb-BTC in our work is among the best compared with other reported MOF anode electrodes.

Stabilization of Superionic-Conducting High-Temperature Phase of Li(CB9H10) via Solid Solution Formation with Li2(B12H12)

We report the stabilization of the high-temperature (high-T) phase of lithium carba-closo-decaborate, Li(CB9H10), via the formation of solid solutions in a Li(CB9H10)-Li2(B12H12) quasi-binary system. Li(CB9H10)-based solid solutions in which [CB9H10]− is replaced by [B12H12]2− were obtained at compositions with low x values in the (1−x)Li(CB9H10)−xLi2(B12H12) system. An increase in the extent of [B12H12]2− substitution promoted stabilization of the high-T phase of Li(CB9H10), resulting in an increase in the lithium-ion conductivity. Superionic conductivities of over 10−3 S cm−1 were achieved for the compounds with 0.2 ≤ x ≤ 0.4. In addition, a comparison of the Li(CB9H10)−Li2(B12H12) system and the Li(CB9H10)−Li(CB11H12) system suggests that the valence of the complex anions plays an important role in the ionic conduction. In battery tests, an all-solid-state Li–TiS2 cell employing 0.6Li(CB9H10)−0.4Li2(B12H12) (x = 0.4) as a solid electrolyte presented reversible battery reactions during repeated discharge–charge cycles. The current study offers an insight into strategies to develop complex hydride solid electrolytes.

Recovering activity of anodically challenged oxygen reduction electrocatalysts by means of reductive potential pulses

The stability of electrocatalysts is of great importance to ensure their applicability, but stability is generally only considered for catalysts polarised to a constant potential or current density. This excludes stability evaluation under start/stop conditions in a fuel cell or in reversible batteries in which the catalyst is alternately polarised to high opposite potentials. For example, the poor cyclability of metal-air batteries is mainly due to the decrease in the oxygen reduction activity of electrocatalysts during the high applied potentials for the oxygen evolution reaction during battery charging. To investigate and at least partially mitigate the loss of electrocatalytic activity for the oxygen reduction reaction, we employed reductive pulses with the aim of restoring the catalytic activity of the active sites for the oxygen reduction reaction. Optimisation of the reductive pulse parameters makes it possible to substantially prolong the oxygen reduction activity of a Fe-Nx-doped carbon-based oxygen reduction electrocatalyst.

Ionic Liquids at the Electrode Interface: Insights into Surface Passivation and Framework Expansion of Hard Carbon Anodes

Ionic liquids are being extensively explored as an alternative to carbonate-based electrolytes in reversible batteries, as they can exhibit lower flammability and volatility, and better overall safety. The polarity and acidity/basicity of ionic liquids can be tuned to control solubility, and can influence the electrochemical window and interfacial properties when used in batteries. In this study, 1-ethyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl) imide (EMIM.TFSI) and 1-methyl-1-propypyrrolidinium bis(trifluoromethanesulfonyl)imide (MPPY.TFSI) were selected because they are well-known, relatively stable ionic liquids with large electrochemical windows which show strikingly different behavior with carbonaceous anodes due to differences in interface passivation. High surface area mesoporous hard carbon anodes were employed to provide a large signal from the interfacial chemistry of these electrolytes during reversible cycling. A combination of operando small-angle neutron scattering (SANS) and ex-situ electrochemical studies were used to understand the differences in solid electrolyte interphase (SEI) for these ionic liquids, and the relationship of SEI formation to hard carbon microstructural changes. Reversible hard carbon expansion is observed in the first cycle for the electrolyte lithium bis(trifluoro-methanesulfonyl)imide (LiTFSI)/EMIM.TFSI related to EMIM+ intercalation and deintercalation before a stable SEI is formed, while a largely irreversible framework expansion of 15% is observed for the LiTFSI/MPPY.TFSI electrolyte. There is only relatively minor expansion and contraction in subsequent cycles after a suitable solid electrolyte interphase (SEI) has formed. Irreversible framework expansion in conjunction with SEI formation is found to be essential for the stable cycling of hard carbon electrodes.[1]Acknowledgement: Research was sponsored by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. Research at Spallation Neutron Source user facility was sponsored by the Division of Scientific User Facilities, Office of Basic Energy Sciences, US Department of Energy, under contract DE-AC05-00OR22725 with UT-Battelle, LLC.[1] Bridges, C.A.; Sun, X.G.; Guo, B.K.; Heller, W.T.; He, L.L.; Paranthaman, M.P.; Dai, S. “Observing Framework Expansion of Ordered Mesoporous Hard Carbon Anodes with Ionic Liquid Electrolytes via in Situ Small-Angle Neutron Scattering.” ACS Energy Lett. 2017, 2, (7), 1698-1704.

Mean Ionic Activity Coefficients of NaBr in the Ternary System NaBr–SrBr2–H2O at 288.15 K using the Cell Potential Method

In this paper, a sodium ion selective electrode (Na-ISE) and a bromide ion selective electrode (Br-ISE) were used to form a liquid-free potential reversible battery: Na-ISE|NaBr (m1) and SrBr2 (m2)...

3D copper-confined N-Doped graphene/carbon nanotubes network as high-performing lithium-ion battery anode

A facile synthesis of three-dimensional (3D) network of copper confined nitrogen-doped graphene (NG)/carbon nanotube (CNT) with high atomic percentage of nitrogen (10.1 at.%) has been reported. The homogenous intercalation of the CNT network in-between the graphene layers decorated with copper nanoparticles take place which inhibits the self-agglomeration within the lattice and enhance the volumetric storage capability. The composite electrode demonstrates exceptionally high specific capacitance of 1250 mA h/g obtained at a current density of 0.1 A/g which is 3.4 times greater than the theoretical capacity of graphite (372 mA h/g). The discharge-charge profiles (from 0.002 to 3 V) with reversible battery capacity exhibit a stable state of the lithium-ion batteries which were observed at high rate capability of 420 mA h/g at a current density of 1 A/g even after 500 cycles. The enhancement of the electrochemical performance could be attributed to the 3D electrically conductive networks of copper confined nitrogen-doped graphene/carbon nanotubes (Cu@[N-Gr/CNT]).