Three-dimensional Current Collector Research Articles

Lithiophilic hollow Co3[Co(CN)6]2 embedded carbon nanotube film for dendrite-free lithium metal anodes

Lithium metal is considered to be an ideal anode material due to its ultra-high theoretical capacity and extremely low electric potential. Unfortunately, the infinite volume expansion and unregulated formation of lithium dendrites in the plating/stripping process restrict its practical utilization. Herein, we designed a hollow Co3[Co(CN)6]2 (CoCoPBA) embedded high-conductivity carbon film as a three-dimensional (3D) lithiophilic current collector (h-CoCoPBAs@SWCNT). The interwoven carbon nanotubes with hollow nanoparticles can effectively promote electron transfer and reduce local current density, adapting to the huge volume expansion in long-term electrochemical cycling. At the same time, lithiophilic hollow CoCoPBA nanoparticles provide abundant active sites due to their large surface area, efficiently reducing nucleation overpotential and making lithium deposition easier and more uniform, both confirmed by theoretical calculation and experiment. Accordingly, compared with bare Cu electrodes, h-CoCoPBAs@SWCNT electrodes have a flat and uniform Li deposition morphology, which is beneficial to enhance the cycle life of lithium metal anodes. And the symmetrical cell assembled by h-CoCoPBAs@SWCNT shows stable cycling performance of more than 500 h at 2 mA cm−2 with 1 mAh cm−2. Besides, the assembled lithium-sulfur full cell also has higher cycle stability and rate performance.

Facile Lithiophilic 3D Copper Current Collector for Stable Li Metal Anode

Lithiophilic hosts are confirmed to effectively enhance the electrochemical stability of lithium (Li) anodes, thereby guaranteeing the safe, practical application of Li metal as the anode in rechargeable Li-ion batteries. This study reveals a lithiophilic three-dimensional copper current collector (Ag@CF). Silver (Ag) nanoparticles were anchored on the surface of a skeleton of copper foam (CF) via a facile displacement reaction under ultrasonic conditions. The introduced Ag nanoparticle layer reduces the nucleation barrier of Li, leading to a homogeneous Li nucleation and plating. Simultaneously, porous Ag@CF provides the structural support and storage volume of the Li anode, eliminating its volume change in the process of plating/stripping. Benefiting from the above, the Ag@CF electrode shows a superior electrochemical performance in half-type cells (near 100% coulomb efficiency for 350 cycles at 1 mA cm−2). Composite electrodes (Li-Ag@CF) preloaded in the Ag@CF network deliver an ultra-long lifespan of over 1600 h with a low over-potential at 1 mA cm−2 in Li-Ag@CF symmetric cells. Furthermore, LiFePO4∣Li-Ag@CF full cells display enhanced capacity retention (over 80% for 800 cycles at 1 or 3 C). More importantly, this method is facile, large-scalable, and low-cost, which offers an alternation strategy for the practical application of stable Li anodes. Graphical Abstract

Forming Solid-Electrolyte Interphases with Rich Grain Boundaries on 3D Lithiophilic Skeleton for Low-Temperature Lithium Metal Batteries

Rational design of the current collector along with further constructing solid electrolyte interphases (SEI) shows great promise to achieve uniform lithium (Li) deposition, specifically at low temperature. Here we report a Li 2 O-Ni based SEI layer with rich grain boundaries formed on the three-dimensional (3D) Ni-NiO current collector for stabilizing Li metal anodes. Different from two-dimensional (2D) substrates, the lithiophilic 3D substrates with porous structures exhibit high binding affinity to Li and provide enough space for volume fluctuation, leading to uniform Li deposition. The grain boundaries between Li 2 O (111) and Ni (111) in the SEI layer display a low diffusion barrier of Li + , facilitating Li + transport through the interface. As a result, Li||NCM811 full cells using 3D Ni-NiO display an excellent cycling stability with capacity retention of 80.8% after 160 cycles under harsh conditions, i.e., a limited Li supply (N/P = 2.4) and a high areal capacity (4.0 mAh cm −2 ). Even at low temperature of -30°C, Li||NCM811 full cells with 3D Ni-NiO exhibit a large areal capacity of 3.2 mAh cm −2 and apparently enhanced cycle life with limited Li anode (N/P = 1.2) compared with non-lithiophilic 3D current collectors. Graphical Abstract .

Mo/Fe bimetallic pyrophosphates derived from Prussian blue analogues for rapid electrocatalytic oxygen evolution

Efficient and stable oxygen evolution electrocatalysts are indispensable for industrial applications of water splitting and hydrogen production. Herein, a simple and practical method was applied to fabricate (Mo, Fe)P2O7@NF electrocatalyst by directly growing Mo/Fe bimetallic pyrophosphate derived from Prussian blue analogues on three-dimensional porous current collector. In alkaline media, the developed material possesses good hydrophilic features and exhibits best-in-class oxygen evolution reaction (OER) performances. Surprisingly, the (Mo, Fe)P2O7@NF only requires overpotentials of 250 and 290 mV to deliver 100 and 600 mA cm−2 in 1 mol L−1 KOH, respectively. Furthermore, the (Mo, Fe)P2O7@NF shows outstanding performances in alkaline salty water and 1 mol L−1 high purity KOH. A worthwhile pathway is provided to combine bimetallic pyrophosphate with commercial Ni foam to form robust electrocatalysts for stable electrocatalytic OER, which has a positive impact on both hydrogen energy application and environmental restoration.

Bifunctional 3D Graphite@Ni-Fe foam negative current collector toward stable liquid metal battery

Negative current collectors play vital roles in the electrochemical performance of liquid metal batteries (LMBs). Employing a three-dimensional (3D) current collector is an effective approach to host molten lithium and reduce the effective current density. The Ni-Fe foam is a frequently used 3D current collector for the negative electrode. However, the corrosion of molten lithium towards the Ni-Fe foam skeleton devastates the 3D structure of the current collector and so deteriorates seriously the electrochemical performance of LMB. To enhance the corrosion resistivity, herein, the graphite layer coated Ni-Fe foam (Graphite@Ni-Fe) is prepared by the chemical vapor deposition method. The prepared scaly-like graphite layer plays a bifunctional role in chemistry, preventing corrosion as an effective barrier and improving remarkably the surface lithiophilicity of Ni-Fe foam. The assembled Li||Bi batteries with Graphite@Ni-Fe foam as negative current collector exhibit stable cycling performance with capacity retention of 98.10% and high Coulombic efficiencies over 98.3% at 0.4 A cm−2 over 100 cycles at 500 °C. More importantly, outstanding rate capability is achieved and almost no capacity degradation is observed upon current density change from 0.2 to 2.0 A cm−2. This work highlights the importance of the lithiophilicity and the corrosion resistance ability of the negative current collectors for LMBs.

Appropriate Properties of Carbon Nanotube for Three-Dimensional Current Collector of Lithium-Ion Battery

Appropriate Properties of Carbon Nanotube for Three-Dimensional Current Collector of Lithium-Ion Battery

Elastic three-dimensional Fe-doped polypyrrole aerogel current collector for high-loading and high-energy-density lithium-sulfur batteries

Development of high-loading and high-energy-density lithium-sulfur (Li-S) batteries has aroused increasing research interests recently. However, the performance of a conventional two-dimensional Al foil current collector is limited by its smooth/nonporous surface and poor flexibility, which is unfavorable for the achievement of high sulfur loading and sufficient polysulfide adsorption. Hence, a three-dimensional porous Fe-doped polypyrrole aerogel (FPA) is developed by a simple and scalable strategy combing the solution reaction with the freeze-drying technique, aiming at acting as the current collector of cathode to address these issues in Li-S batteries. This FPA possesses a conductive porous network structure with high elasticity and abundant Fe dopants, which can not only buffer the large volume change of sulfur and ensure fast ion/electron transfer, but also effectively anchor the polysulfides and lower the negative polarization effect during cycling. As a result, the FPA@S cathode delivers a high initial capacity of 1196.7 mAh g−1 at 0.2 C and a retained capacity of 829.5 mAh g−1 after 200 cycles, with stabilized Coulombic efficiency and excellent rate performance. This FPA@S cathode also achieves a high cell-level gravimetric energy density of 199.7 Wh kgcell−1 even under a high sulfur-loading (8.57 mg cm−2) and low electrolyte/sulfur ratio (6 mL g−1), demonstrating its practical potential in future advanced high-energy battery systems.

Communication—Cross-Linked Anionic Polymer Coating Prepared by UV and Thermal Curing for Long-Life Lithium-Sulfur Battery

An anionic polymer coating produced by ultraviolet curing and thermosetting to suppress polysulfide dissolution of the sulfur cathode for lithium-sulfur batteries was investigated. An sulfur/Ketjenblack cathode with a high sulfur loading of 10 mg cm−2 was prepared using a three-dimensional foam current collector. From the current rate and cycle characteristics, the cross-linked polymer coating suppressed the polysulfide dissolution, and the discharge capacities were 1031 and 414 mAh g−1-sulfur at 0.1 and 1.0C, respectively. In a long-term cycle test of 300 cycles, a capacity retention rate was 41%. An average coulombic efficiency was 91% throughout the cycles.

Quantitatively Designing Porous Copper Current Collectors for Lithium Metal Anodes

Lithium metal has been an attractive candidate as a next-generation anode material. Despite its popularity, stability issues of lithium in the liquid electrolyte and the formation of lithium whiskers have kept it from practical use. Three-dimensional (3D) current collectors have been proposed as an effective method to mitigate whiskers growth. Although extensive research has been done, the effects of three key parameters of the 3D current collectors, namely the surface area, the tortuosity factor, and the surface chemistry, on the performance of lithium metal batteries remain elusive. Herein, we quantitatively studied the role of these three parameters by synthesizing four types of porous copper networks with different sizes of well-structured micro-channels. X-ray microscale computed tomography (micro-CT) allowed us to assess the surface area, the pore size and the tortuosity factor of the porous copper materials. A metallic Zn coating was also applied to study the influence of surface chemistry on the performance of the 3D current collectors. The effects of these parameters on the performance were studied in detail through Scanning Electron Microscopy (SEM) and Titration Gas Chromatography (TGC). Stochastic simulations further allowed us to interpret the role of the tortuosity factor in lithiation. The optimal range of the key parameters is thereby found for the porous coppers and their performance is predicted. Using these parameters to inform the design of porous copper anodes for Li deposition, Coulombic efficiencies (CE) of up to 99.63% are achieved, thus paving the way for the design of effective 3D current collector systems.

Exchange of Li and AgNO3 Enabling Stable 3D Lithium Metal Anodes with Embedded Lithophilic Nanoparticles and a Solid Electrolyte Interphase Inducer.

Three-dimensional (3D) current collectors can effectively mitigate the volumetric expansion of working lithium metal anodes (LMAs). However, the practical utilization of 3D current collectors for lithium metal batteries remains unsatisfactory because of inhomogeneous deposition of lithium ions and an unstable solid electrolyte interphase (SEI). Herein, a facile method based on the exchange reaction between Li and AgNO3 is exploited to embed Ag nanoparticles (NPs) and LiNO3 in a carbon paper (ALCP@Li). The Ag NPs act as a seed for even lithium deposition inside the carbon matrix by virtue of their excellent lithiophilicity. Simultaneously, LiNO3 plays an effective role in stabilizing LMAs by evolving a robust N-rich SEI. As a result, such 3D LMAs show a high Coulombic efficiency in half-cells (200 cycles, 99% at 1 mA cm-2, 1 mAh cm-2) and a low overpotential (60 mV). When paired with commercial thick NCM622 and LiFePO4 cathodes, the 3D LMA-based full cells exhibit stable cycling in carbonate electrolytes.

Three-dimensional foam-type current collectors for rechargeable batteries: A short review

Energy storage systems as lithium-ion batteries (LIBs) have become an essential part of our lives, powering on-the-go technologies we use every day. Until recently, immense attention was paid to designing and synthesizing advanced active materials for LIBs to enhance the battery characteristics. However, not the least crucial part of the battery, the current collector, was left unattended for a long time. Therefore, it is not surprising that the batteries reached their limits in power and energy densities, leaving the battery progress equal to an almost flat line. The only way to go ahead with the battery technology would be to design new architectures or to investigate new materials. Changing the battery current collector from planar to three-dimensional (3D) would offer dimensionality to the electrodes meaning short diffusion length for Li-ions, which will boost power density, more active material, and mechanical stability. Herein, in this review, various 3D architecture current collectors will be summarized, and recent advances in synthesis routes will be discussed to point out the importance of 3D structures. In addition, the correlation between the electrochemical performances of batteries and current collector architecture will be reviewed. More than 50 research publications related to the synthesis and performance of different 3D current collectors were reviewed and compared. The review results suggest that despite the outstanding performance, currently used technologies to obtain 3D current collectors make them unacceptable in the commercial sphere, and cheaper, faster and simple synthesis routes are desired to be explored. • Three-dimensional foam-type current collectors for rechargeable batteries have been reviewed. • Different preparation methods of foam type current collectors have been overviewed. • Performances of different foam type current collectors are discussed.

Coordinated layout planning of ocean current turbines and collector system considering spatial velocity distribution

Ocean current generation has become a popular form of supplying electric energy by using fluid kinetic energy. For ocean current, the key difference from other planning can be embodied in the turbine layout planning region, which needs to be considered as a three-dimensional area. Considering that, this paper investigates the three-dimensional ocean current turbines and collector system coordinated layout planning model. First, a velocity-depth curve of interest current area is determined by fitting historical velocity data. Then, a three-dimensional ocean current wake model is derived through the integral form of momentum conservation to analyze the influence of the wake effect on the velocity of the three-dimensional distributed turbine array. Finally, a two-level three-dimensional location and capacity planning model is established which involve three-dimensional topology constraints, with the upper-level goal of minimizing the whole system cost, and the lower-level goal of minimizing the cost of power collection topology. The accuracy and effectiveness of the proposed model are investigated through the case study on the current data of the Gulf of Mexico.

Quantitatively Designing Porous Copper Current Collectors for Lithium Metal Anodes

Author(s): Lu, B; Olivera, E; Scharf, J; Chouchane, M; Fang, C; Ceja, M; Pangilinan, LE; Zheng, S; Dawson, A; Cheng, D; Bao, W; Arcelus, O; Franco, AA; Li, X; Tolbert, SH; Meng, YS | Abstract: Lithium metal has been an attractive candidate as a next-generation anode material. Despite its popularity, stability issues of lithium in the liquid electrolyte and the formation of lithium whiskers have kept it from practical use. Three-dimensional (3D) current collectors have been proposed as an effective method to mitigate whisker growth. Although extensive research has been done, the effects of three key parameters of the 3D current collectors, namely, the surface area, the tortuosity factor, and the surface chemistry, on the performance of lithium metal batteries remain elusive. Herein, we quantitatively studied the role of these three parameters by synthesizing four types of porous copper networks with different sizes of well-structured microchannels. X-ray microscale computed tomography (micro-CT) allowed us to assess the surface area, the pore size, and the tortuosity factor of the porous copper materials. A metallic Zn coating was also applied to study the influence of surface chemistry on the performance of the 3D current collectors. The effects of these parameters on the performance were studied in detail through scanning electron microscopy (SEM) and titration gas chromatography (TGC). Stochastic simulations further allowed us to interpret the role of the tortuosity factor in lithiation. The optimal range of the key parameters is thereby found for the porous coppers and their performance is predicted. Using these parameters to inform the design of porous copper anodes for Li deposition, Coulombic efficiencies (CEs) of up to 99.63% are achieved, thus paving the way for the design of effective 3D current collector systems.

Effect of Washing on the Electrochemical Performance of a Three-Dimensional Current Collector for Energy Storage Applications.

The development of efficient materials for energy storage applications has attracted considerable attention, especially for supercapacitors and batteries that are the most promising and important power sources in everyday life. For this purpose, a suitable and efficient current collector must be determined and its behavior with respect to various solvents when it is used as an electrode material for energy storage applications should be understood. In this work, we studied the effect of washing three-dimensional nickel foam using different concentrations of hydrochloric acid and ethanol on the surface characteristics, electrochemical behavior, and storage performance of the foam. Additionally, we observed the different types of acidic treatments that improved the electrochemical and storage performances of the three-dimensional nickel foam. The surface characterization results show that acidic conditions with a concentration of 3M changes the surface morphology from a flat/hill-like structure to a nanosheet/nanoflake-like structure without any further treatment. This structure provides a nano-channel and a large number of surface charges during the electrochemical reaction. The results of this study show that pretreatment of 3D-NF is highly important and recommended. The present work also contributes to the knowledgebase on pretreatment of 3D-NF and its optimization.

Fabrication of three-dimensional porous Cu current collector for lithium-ion batteries using Space Holder Method

Fabrication of three-dimensional porous Cu current collector for lithium-ion batteries using Space Holder Method

“Mechanical–electrochemical” coupling structure and the application as a three-dimensional current collector for lithium metal anode

To construct a lithiophilic-lithiophobic gradient collector has been regarded as an effective strategy to address the challenge of lithium dendrite growth in Li metal anode. However, it was also found that the uneven stress accumulation, induced by the directional deposition, would cause fatigue-like failure in the gradient structure. In this work, a hybrid carbon nano fiber (CNF) structure, consisting of a gradient nitrogen doping CNF layer and a Cu doped CNF layer, was fabricated. The Cu-decorated carbon nanofibers not only provide a deposits-free (lithiophilic) surface, but also act as “reinforcing rib” to resist the fatigue stress. The unique hybrid structure delivered a high Coulomb efficiency and resistance to repeat stress application.

High-energy-density Li–S battery with positive electrode of lithium polysulfides held by carbon nanotube sponge

Lithium-sulfur battery suffers from the low utilization of sulfur and the high electrolyte/sulfur (E/S) ratio that decrease the cell-based performance. Lithium polysulfides (Li2Sx)-dissolved electrolyte, so called catholyte, enables high utilization of sulfur, but the cell inherently has high E/S ratio due to the limited solubility of Li2Sx. Herein, a composite electrode of Li2Sx (x = 4, 6, 8) and sub-millimeter-long few-wall carbon nanotube (CNT) is proposed. The CNT forms self-supporting sponge-like paper and works as a three-dimensional current collector, in which the Li2Sx is deposited by solution casting and drying. The Li2S6-CNT electrode realizes high specific capacity (1249 mAh gsulfur−1) under a lean electrolyte condition of E/S = 4 μL mgsulfur−1, which is much better than the S8-CNT electrode (233 mAh gsulfur−1). After full charge and conversion of Li2Sx to S, the Li2Sx-CNT electrode maintains its high capacity of 1100 mAh gsulfur−1. The full cell with the Li2S6-CNT and the Li thin foil electrodes realizes 400–500 Wh kgcell−1 for E/S = 4.0 at the 2nd and 3rd discharge and 300 Wh kgcell−1 for E/S = 5.8 at the 97th discharge, based on the total mass of the interior of a cell (electrodes, separator, and electrolyte). Holding solvated Li2Sx by the CNT sponge is the key for the high energy density.

3D Printed Lithium-Metal Full Batteries Based on a High-Performance Three-Dimensional Anode Current Collector

A three-dimensional (3D) printing method has been developed for preparing a lithium anode base on 3D-structured copper mesh current collectors. Through in situ observations and computer simulations, the deposition behavior and mechanism of lithium ions in the 3D copper mesh current collector are clarified. Benefiting from the characteristics that the large pores can transport electrolyte and provide space for dendrite growth, and the small holes guide the deposition of dendrites, the 3D Cu mesh anode exhibits excellent deposition and stripping capability (50 mAh cm-2), high-rate capability (50 mA cm-2), and a long-term stable cycle (1000 h). A full lithium battery with a LiFePO4 cathode based on this anode exhibits a good cycle life. Moreover, a 3D fully printed lithium-sulfur battery with a 3D printed high-load sulfur cathode can easily charge mobile phones and light up 51 LED indicators, which indicates the great potential for the practicability of lithium-metal batteries with the characteristic of high energy densities. Most importantly, this unique and simple strategy is also able to solve the dendrite problem of other secondary metal batteries. Furthermore, this method has great potential in the continuous mass production of electrodes.

Recent Progress and Perspectives of Sodium Metal Anodes for Rechargeable Batteries

Sodium metal anodes have attracted significant attention due to their high specific capacity, low redox potential and abundant resources. However, the dendrites and unstable solid electrolyte interphase(SEI) of sodium anodes restrict the development of sodium metal batteries. This review includes the recent progress on the Na anode protection in sodium metal batteries. The strategies are summarized as modified three-dimensional current collectors, artificial solid electrolyte interphases, and electrolyte modifications. Conclusions and perspectives are envisaged for the further understanding and development of Na metal anodes.

Study on the Cycling Performance of Li-Metal Anodes Impregnated into 3D Current Collectors for Li-Metal Batteries

Lithium (Li) metal is the most attractive anode material for batteries because of its high specific capacity (3861 mAh/g) and low negative potential (- 3.04 V vs. NHE). However, the Li dendrite growth during Li deposition leads to serious safety problems and poor cycling performance. With durative forming and growing of the Li dendrite during cycling, the accompanying large surface area of SEI layers induces a constant loss of both working Li metal and electrolyte, leading to a low Coulombic efficiency and a rapid capacity decay. Thus, there has been much research effort to achieve the suppression of the Li dendrite formation.According to the previous reports, employing three-dimensional (3D) current collectors is one approach to reduce the effective current density and delay dendrite growth. In this study, we developed a strategy by impregnating Li metal into the 3D current collectors of nickel (Ni) foam and carbon (C) foam backbone to improve the cycling performance of Li-metal anodes for Li-metal batteries. As a result, Li @ Ni foam and Li @ C foam cells showed better capacity retention for 500 cycles than pure Li metal anodes.