Three-dimensional Current Collector Research Articles

Lightweight 3D Lithiophilic Graphene Aerogel Current Collectors for Lithium Metal Anodes.

Constructing three-dimensional (3D) current collectors is an effective strategy to solve the hindrance of the development of lithium metal anodes (LMAs). However, the excessive mass of the metallic scaffold structure leads to a decrease in energy density. Herein, lithiophilic graphene aerogels comprising reduced graphene oxide aerogels and silver nanowires (rGO-AgNW) are synthesized through chemical reduction and freeze-drying techniques. The rGO aerogels with large specific surface areas effectively mitigate local current density and delay the formation of lithium dendrites, and the lithiophilic silver nanowires can provide sites for the uniform deposition of lithium. The rGO-AgNW/Li symmetric cell presents a stable cycle of about 2000 h at 1 mA cm-2. When coupled with the LiFePO4 cathode, the assembled full cells exhibit outstanding cycle stability and rate performance. Lightweight rGO-AgNW aerogels, as the host for lithium metal, can significantly improve the energy density of lithium metal anodes.

Energy-dense aqueous Zn//MnO2 rechargeable battery constructed on dual three-dimensional conductive skeletons

Enhancing the energy density of aqueous rechargeable zinc-based batteries is critical for boosting their application in a variety of practical scenarios. Herein we demonstrate a strategy to improve specific energies of Zn//MnO2 batteries in mild electrolyte via utilizing three-dimensional (3D) current collectors for both the anode and cathode. By electrodepositing limited amounts of Zn on surface-alloyed Ag mesh and coupling it with MnO2 cathode electrodeposited on carbon cloth with no binder, the resultant batteries exhibit specific energy up to 253 and 196 Wh/kg (based on total mass of active materials) at negative-to-positive electrode capacity (N/P) ratios of 1:1 and 2:1. By elevating the working temperature to 35 °C, the specific energy and life span of the battery with N/P = 2 can be further increased to 216 Wh/kg and >225 cycles, respectively. The key to achieving a high specific energy relies primarily on the great reversibility of the Zn anode, which is conferred by the 3D Ag mesh.

Structural Design of 3D Current Collectors for Lithium Metal Anodes: A Review.

Due to the ultrahigh theoretical specific capacity (3860 mAh g-1) and low redox potential (-3.04 V vs. standard hydrogen electrode), Lithium (Li) metal anode (LMA) received increasing attentions. However, notorious dendrite and volume expansion during the cycling process seriously hinder the development of high energy density Li metal batteries. Constructing three-dimensional (3D) current collectors for Li can fundamentally solve the intrinsic drawback of hostless for Li. Therefore, this review systematically introduces the design and synthesis engineering and the current development status of different 3D collectors in recent years (the current collectors are divided into two major parts: metal-based current collectors and carbon-based current collectors). In the end, some perspectives of the future promotion for LMA application are also presented.

Gradient three-dimensional current collector with lithiophilic nanolayer regulation for efficient lithium metal anode construction

Metallic lithium (Li) is highly desirable for Li battery anodes due to its unique advantages. However, the growth of Li dendrites poses challenges for commercialization. To address this issue, researchers have proposed various three-dimensional (3D) current collectors. In this study, the selective modification of a 3D Cu foam scaffold with lithiophilic elements was explored to induce controlled Li deposition. The Cu foam was selectively modified with Ag and Sn to create uniform Cu foam (U-Cu) and gradient lithiophilic Cu foam (G-Cu) structures. Density Functional Theory (DFT) calculations revealed that Ag exhibited a stronger binding energy with Li compared to Sn, indicating superior Li induction capabilities. Electrochemical testing demonstrated that the half cell with the G-Cu@Ag electrode exhibited excellent cycling stability, maintaining 550 cycles with an average Coulombic efficiency (CE) of 97.35%. This performance surpassed that of both Cu foam and G-Cu@Sn. The gradient modification of the current collectors improved the utilization of the 3D scaffold and prevented Li accumulation at the top of the scaffold. Overall, the selective modification of the 3D Cu foam scaffold with lithiophilic elements, particularly Ag, offers promising prospects for mitigating Li dendrite growth and enhancing the performance of Li batteries.

One-stone, two birds: Three-dimensional structure and rich-inorganic solid electrolyte interface derived from Bi nanoparticles modified Ti3C2/CNT/rGO aerogel for anode-free potassium metal batteries

Potassium (K) metal batteries are very promising next generation electrochemical energy storage system due to the usage of K metal with low cost and high energy density. However, the practical application of K metal batteries and even anode-free K metal batteries are still confronting huge challenges owing to the formation of “dead K” resulting from the uncontrollable growth of K dendrite and the infinite volume variation, as well as the continuous consumption of electrolyte component during charge/discharge processes. Herein, a novel “one-stone, two birds” strategy was proposed for the first time by designing a three-dimensional (3D) potassiophilic current collector composed of“Bi nanoparticles modified Ti3C2/CNT/rGO cross-linked 3D porous aerogel hosts (marked as Bi/CTG)”and spontaneously in-situ forming a rich-inorganic SEI layer simultaneously. The modification of Bi nanoparticles could improve potassiophilicity of hosts and guide uniform K metal deposition. The 3D porous structure of Bi/CTG hosts could accommodate the deposited K metal to restrain serious volume variation during K plating/stripping process. Simultaneously, the spontaneous generation of KF and K3Bi between the deposited K metal and Bi/CTG could contribute SEI layer and improve the stability of SEI layer. The integrated merits are conductive to realize stable and reversible cycling of anode-free K metal battery. As a result, Bi/CTG@Cu//PB anode-free K metal battery delivers extraordinary energy density of 152.8 Wh kg−1 at a power density of 6110 W kg−1. This study paves the way to realize high energy density anode-free K metal battery through a simple “one-stone, two birds” strategy.

Three-dimensional copper current collector as an anode for rechargeable anode-less lithium-ion batteries

The formation of dendrites presents a significant challenge that hampers the performance of lithium metal batteries, leading to rapid capacity degradation, low coulombic efficiency, and potential short circuits. In this regard we have engineered a rechargeable lithium metal battery without a conventional anode – lithium, employing commercially available LiNi1/3Co1/3Mn1/3O2 as a cathode and enhanced three-dimensional copper foam current collector as an anode. The modification of the three-dimensional copper foam current collector with gold effectively reduced the local current density while providing a substantial surface area for lithium deposition. Moreover, our approach incorporates a blend of salts, namely lithium bis(trifluoromethanesulfonyl)imide and lithium difluoro(oxalato)borat, resulting in an impressive reversible capacity of 100 mAh g−1 with an outstanding coulombic efficiency of 99.9% after 50 cycles. These discoveries hold particular significance in the advancement of next-generation energy storage systems characterized by high energy density and immunity to dendrite formation.

Direct-spun carbon nanotube sheet: A flexible, ultralight, stackable three-dimensional current collector for high-performance lithium-ion batteries

Among the key components of a battery electrode, current collectors hold significant importance for the energy density of lithium ion batteries (LIBs) as metal foils account for a significant proportion of the total mass. Carbon nanotube sheet (CNTS) has garnered considerable attention because of its fascinating material features such as high electrical conductivity, low density, and excellent flexibility. In this study, we demonstrate the utilization of a direct-spun CNTS as a current collector in order to enhance the electrochemical performance and replace the conventional current collector, that is, aluminum (Al) foil, in LIBs. When the CNTS coated with NCM811 (NCM811/CNTS) is evaluated in LIBs, it delivers superior rate capability and cycle stability compared with Al foil-based and buckypaper-based NCM811 electrodes. It is because the CNTS with a large surface area and high electrical conductivity establishes a number of electronic pathways to the cathode electrode. In addition, the porous structure of the CNTS efficiently enhances the adhesive properties of the electrodes. Due to the synergistic benefits of CNTS, cells with stacked NCM811/CNTS electrodes are successfully fabricated. Electrode stacking with multiple NCM811/CNTS electrodes exhibits improved areal capacity and stable cycle stability, suggesting a new strategy to replace the concept of conventional thick electrodes. Moreover, pouch cells with LTO/CNTS as an anode and NCM811/CNTS as a cathode display stable electrochemical performance even under mechanical deformation (e.g., folding/unfolding)

An Improved Lithium-Sulfur Battery By Using Porous Carbon As the Sulfur Template

As global demand for electric vehicles (EVs) continues to rise, the rechargeable battery of high-energy density is actively researched. Lithium-ion batteries (LIBs) have been widely used in the electric vehicles (EVs) and have been leading the EVs market. However, LIBs have reached their limits due to their practical low-capacity and high-cost. Therefore, novel strategy is required to solve the problem of the LIBs.Lithium-sulfur (Li-S) batteries attract attention because of high theoretical capacity (1675 mAh/g) and high energy density (2600 Wh/kg). Moreover, sulfur as electrode material is abundant and inexpensive. However, the sulfur-based batteries have serious disadvantages, which is the shuttle of intermediate polysulfides (Li2Sn, 2<n≤8), and low conductivity, result in poor cycle stability and low discharge capacity [1,2].Therefore, in this study, the sulfur electrode is fabricated by impregnating sulfur into three-dimensional porous carbon. The porous structure suppressed the dissolution/shuttle of sulfur species and improved the cycling stability and discharge capacity. Moreover, three types of porous carbon templated of activated carbon cloth, activated carbon felt, and porous carbon foam were compared on electrochemical performances.Reference Jimin Yun, 2023, High Loading Sulfur Cathode with Three-dimensional Porous Current Collector for Lithium-Sulfur Battery, Department of Materials Engineering and Convergence Technology, Gyeongsang National University, P.11, p.14Kimin Park, 2022, Design od metal phosphate based electrodes for high-performance Li-Ion & Li-S battery, Department of materials science and engineering seoul national university, P.1

Self-supported 3D current collector modified with in-situ formed lithiophilic [Cu(NH3)2]Cl for high-performance Li-metal batteries

Li-metal batteries (LMBs) are regarded as some of the most promising energy storage systems owing to their superior theoretical specific capacity and lowest electrochemical potential. However, the application of LMBs has been severely hindered by the uncontrollable dendrite growth and volume expansion of metal anodes during Li plating. Herein, we construct a three-dimensional (3D) porous CuZn current collector decorated with a lithiophilic [Cu(NH3)2]Cl compound (3D 1H3N), in which [Cu(NH3)2]Cl offers nucleation sites and guides fast Li+ deposition in the pores and tunnels. The 3D framework accommodates volume expansion and disperses deposition current. Together, these two functions contribute to low-barrier and dendrite-free Li plating/stripping with enhanced Coulombic efficiency (CE) and excellent stability. The half-cell utilizing the as-fabricated 3D 1H3N current collector exhibited a CE of 98 % for over 270 cycles at 0.5 mA·cm–2 and 97 % for over 220 cycles at 1 mA·cm–2. The Li@3D 1H3N anode stabilized over 270 cycles (1100 h) at 0.5C in symmetric cells and delivered a capacity retention of 92.5 % after 450 cycles at 1C (1C = 170 mAh·g–1) in full cells. This study sheds light on the multifunction modification of self-supported anode current collectors for advanced LMBs to promote their practical application.

Rectorite in flow-electrode capacitive deionization with three-dimensional current collector to achieve cost-effective desalination

The innovative design of collector is a top priority to drive the advancement of flow electrode capacitive deionization (FCDI) technology. Currently, the majority of FCDI research has concentrated on the implementation and modification of carbon-based flow electrode materials, while ignoring the effect of the current collector in FCDI. In this study, a 3D-FCDI configuration with porous titanium foam as the collector is designed, and rectorite (Rec) is used as the flow electrode in 3D-FCDI. Thanks to the porous structure of the 3D current collector, the collision opportunities of electrons with the Rec particles are increased and the long-distance migration of electrons in the conventional graphite collector is overcome, thus improving the system conductivity. The Rec exhibits good electrode dispersion, desalination rate, and energy consumption at low cost. In addition, the ASAR of Rec can be achieved by adjusting the electrode concentration (5 wt%), electrode flow rate (25 mL min−1) and operating voltage (1.8 V) to 11.43 μg cm−2 min−1. This study demonstrates the capability of 3D-FCDI configuration to advance the creation and implementation of FCDI.

A stable full cell having high energy density realized by using a three-dimensional current collector of carbon nanotubes and partial prelithiation of silicon monoxide

The prelithiation of SiO-based negative electrodes is essential for stable and high-energy-density Li secondary batteries. In this study, a new partial prelithiation method by two-stack electrodes was developed using lightweight and high-capacity carbon-coated silicon monoxide (SiO/C) films held in a sponge-like matrix of carbon nanotubes (CNTs). The charge-discharge cycles of a full cell with the partially prelithiated SiO/C-CNT negative electrode (p-LixSiO/C-CNT with SiO/C content of 85 mass%) and LiNi0.8Mn0.1Co0.1O2 (NCM811)-CNT positive electrode (NCM content of 97 mass%) reduced the irreversible capacity, achieving high energy densities per the total mass of the negative and positive electrodes of 542 and 420 W h kgelectrode−1 at the 1st and 300th cycle, respectively, with high areal capacities of 4.6 and 3.1 mA h cm−2 for the negative and positive electrodes. The flexible CNT sponge matrix expanded/shrunk reversibly during lithiation/delithiation and retained its structure, whereas the thin Li metal formed Li dendrites and dead Li after cycling, as demonstrated by scanning electron microscopy. The partial prelithiation method of simply stacking the pristine SiO/C-CNT film with a fully prelithiated film enables the careful control of the degree of prelithiation, contributing to full cells of various chemistries.

Gradient Lithium Metal Infusion in Ag-Decorated Carbon Fibers for High-Capacity Lithium Metal Battery Anodes.

Lithium (Li) metal is a promising anode material for high-energy-density Li batteries due to its high specific capacity. However, the uneven deposition of Li metal causes significant volume expansion and safety concerns. Here, we investigate the impact of a gradient-infused Li-metal anode using silver (Ag)-decorated carbonized cellulose fibers (Ag@CC) as a three-dimensional (3D) current collector. The loading level of the gradient-infused Li-metal anode is controlled by the thermal infusion time of molten Li. In particular, a 5 s infusion time in the Ag@CC current collector creates an appropriate space with a lithiophilic surface, resulting in improved cycling stability and a reduced volume expansion rate. Moreover, integrating a 5 s Ag@CC anode with a high-capacity cathode demonstrates superior electrochemical performance with minimal volume expansion. This suggests that a gradient-infused Li-metal anode using Ag@CC as a 3D current collector represents a novel design strategy for Li-metal-based high-capacity Li-ion batteries.

Synthesis of an Advanced Sulfur Cathode with a Porous Graphitic C/Fe3C Electrocatalyst and Three-Dimensional Current Collector for Li–S Batteries

Synthesis of an Advanced Sulfur Cathode with a Porous Graphitic C/Fe₃C Electrocatalyst and Three-Dimensional Current Collector for Li–S Batteries

Three-Dimensional Octahedral Nanocrystals of Cu2O/CuF2 Grown on Porous Cu Foam Act as a Lithophilic Skeleton for Dendrite-Free Lithium Metal Anode.

Metallic-lithium (Li) anodes are highly sought-after for next-generation energy storage systems due to their high theoretical capacity and low electrochemical potential. However, the commercialization of Li anodes faces challenges, including uncontrolled dendrite growth and volume changes during cycling. To address these issues, we developed a novel three-dimensional (3D) copper current collector. Here, we propose a two-step method to fabricate Cu2O/CuF2 octahedral nanocrystals (ONCs) onto 3D Cu current collectors. The resulting Cu foam with distributed ONCs provides active electrochemical sites, promoting uniform Li nucleation and dendrite-free Li deposition. The stable Cu2O/CuF2 ONCs@CF metallic current collector serves as a reliable host for dendrite-free lithium metal anodes. Additionally, the highly porous copper foam with a preconstructed conductive framework of Cu2O/CuF2 ONCs@CF effectively reduces local current density, suppressing volume changes during Li stripping and plating. The symmetric cell using Cu2O/CuF2 ONCs@CF metallic current collector exhibits excellent stability, maintaining over 1600 h at 1 mA cm-2 and a highly stable Coulombic efficiency of 98% over 100 cycles at the same current density, outperforming Li@CuF metallic current collectors. Furthermore, in a full-cell configuration paired with nickel-rich layered oxide cathode materials (Li@Cu2O/CuF2 ONCs@CF//NMC-811), the proposed setup demonstrates exceptional rate performance and an extended cycle life. In conclusion, our work presents a promising strategy to address Li anode challenges and highlights the exceptional performance of the Cu2O/CuF2 ONCs@CF metallic current collector, offering potential for high-capacity and long-lasting lithium-based energy storage systems.

Regulating the intrinsic electronic structure of carbon nanofibers with high-spin state Ni for sodium storage with high-power density

Carbon nanofibers (CNFs) with high specific surface area show great potential for sodium storage as a hard carbon material. Herein, CNFs anchored with Ni nanoparticles (CNFs/Ni) were prepared through chemical vapor deposition and impregnation reduction methods, in situ growing on the three-dimensional porous copper current collector (3DP-Cu). The coupling effect of high-spin state Ni nanoparticles leads to the increase of defect density and the expansion of lattice spacing of CNFs. Meanwhile, the 3DP-Cu ensures a high loading capacity of CNFs and short ion/electron transport channels. As an integral binder-free anode, the 3DP-Cu/CNFs/Ni exhibits excellent electrochemical performance, which demonstrates a high specific capacity with 298.5 mAh g–1 at 1000 mA g–1 after 1500 cycles, and a high power density with 200 mAh g–1 over 1000 cycles at 5000 mA g–1. Density functional theory calculation results show that the high-spin state Ni regulates the electronic structure of CNFs, which significantly reduces the adsorption energy for Na+ (–2.7 Ev) and thus enables high-rate capability. The regulation of the electronic structure of carbon materials by high-spin state metal provides a new strategy for developing high-power carbonaceous anode materials for sodium-ion batteries.

Effect of 3D lithiophilic current collector for anode-free Li ion batteries

The realization of anode-free lithium metal batteries (AFMBs) is limited owing to low Coulombic efficiency derived from the formation of uneven lithium plating at the anode side. Here, we induce the uniform deposition of lithium by an Au predeposited three-dimensional (3D) anodic current collector with an ether-based electrolyte. At the modified anodic current collector, the over-potential generated during the initial deposition of lithium converged to 6 mV, and stable cycling was achieved with an extremely high Coulombic efficiency of 99 % over 100 cycles. Furthermore, when compared to two-dimensional (2D) bare copper foil (LiFePO4/2D Cu), AFMBs using LiFePO4 cathode with Au predeposited 3D anodic current collector (LiFePO4/Au-3D Cu) show better rate performance and longer cycle life. This improvement in electrochemical performance is derived from the regulation of lithium deposition and inhibition of electrolyte decomposition due to the local current density through the predeposition of Au and 3D structure. This study provides a new path to realizing AFMBs.

A Gradient Lithiophilic Structure for Stable Lithium Metal Anodes with Ultrahigh Rate and Ultradeep Capacity.

Using three-dimensional current collectors (3DCC) as frameworks for lithium metal anodes (LMAs) is a promising approach to inhibit dendrite growth. However, the intrinsically accumulated current density on the top surface and limited Li-ion transfer in the interior of 3DCC still lead to the formation of lithium dendrites, which can pose safety risks. In this study, it reports that gradient lithiophilic structures can induce uniform lithium deposition within the interior of the 3DCC, greatly suppressing dendrite formation, as confirmed by COMSOL simulations and experimental results. With this concept, a gradient-structured zinc oxide-loaded copper foam (GSZO-CF) is synthesized via an easy solution-combustion method at low cost. The resulting Li@GSZO-CF symmetric cells demonstrate stable cycling performance for over 800 cycles, with an ultra-deep capacity of 10 mAh cm-2 even under an ultra-high current density of 50mA cm-2 , the top results reported in the literature. Moreover, when combined with a LiFePO4 (LFP) cathode under a low negative/positive (N/P) capacity ratio of 2.9, the Li@GSZO-CF||LFP full cells exhibit stable performance for 200 cycles, with a discharge capacity of 130 mAh g-1 and retention of 85.5% at a charging/discharging rate of 1C. These findings suggest a promising strategy for the development of new-generation LMAs.

Si–Ni-alloy-assisted very high-areal-capacity silicon-based anode on Ni foam for lithium ion battery

Silicon is investigated as an active material for the anode of lithium-ion battery (LIB) because of the 10 times higher specific capacity of silicon than graphite. In order to achieve a low internal resistance and high areal capacity of a silicon-based anode, metal foams are used as three-dimensional current collectors. However, unless the foam is densely compressed, active materials adhere loosely to the foam and suffer from loss of electrical contacts with the current collector. A densely compressed anode suffers from poor physical integrity without spare room for large volume expansion of silicon. By means of pyrolysis at 800 °C in argon of a mixture of silicon nanoparticles, phenolic resin binder, and Super P conductivity agent on the nickel foam, silicon reacts with nickel to form nickel silicide while the specially selected binder is graphitized to form a conductive and porous anode with a nickel foam current collector. We report 80-nm-silicon-based anode with a nickel foam, exhibiting excellent cycling performance and a high retained areal capacity of 6.5 mAh/cm2 after 50 cycles under a discharge/charge current density of 4 mA/cm2. For anode area of 1 cm2, it stores 23.4 C of charges at a current rate of 4 mA.

Constructing 3D Skeleton on Commercial Copper Foil via Electrophoretic Deposition of Lithiophilic Building Blocks for Stable Lithium Metal Anodes.

Lithium (Li) metal has been regarded as the "Holy Grail" of Li battery anodes thanks to its high theoretic specific capacity and low reduction potential, but uneven formation of Li dendrites and uncontrollable Li volume changes hinder the practical applications of Li metal anodes. A three-dimensional (3D) current collector is one of the promising strategies to address the above issues if it can be compatible with current industrialized process. Here, Au-decorated carbon nanotubes (Au@CNTs) are electrophoretically deposited on commercial Cu foil as a 3D lithiophilic skeleton to regulate Li deposition. The thickness of the as-prepared 3D skeleton can be accurately controlled by adjusting the deposition time. Benefitting from the reduced localized current density and improved Li affinity, the Au@CNTs-deposited Cu foil (Au@CNTs@Cu foil) achieves uniform Li nucleation and dendrite-free Li deposition. Compared with bare Cu foil and CNTs deposited Cu foil (CNTs@Cu foil), the Au@CNTs@Cu foil exhibits enhanced Coulombic efficiency and better cycling stability. In the full-cell configuration, the Au@CNTs@Cu foil with predeposited Li shows superior stability and rate performance. This work provides a facial strategy to directly construct a 3D skeleton on commercial Cu foils with lithiophilic building blocks for stable and practical Li metal anodes.

Appropriate properties of carbon nanotubes for the three-dimensional current collector in lithium-ion batteries

Appropriate properties of carbon nanotubes for the three-dimensional current collector in lithium-ion batteries