Lithium fluorosulfonate-induced low-resistance interphase boosting low-temperature performance of commercial graphite/LiFePO4 pouch batteries.

The performance of Li-ion batteries (LIBs) at sub-ambient temperatures is limited by the resistive interphases due to electrolyte decomposition, particularly on the anode surface. In this study, lithium fluorosulfonate (LFS) was added to commercial electrolytes to enhance the low-temperature electrochemical performance of LiFePO4 (LFP)/graphite (Gr) pouch cells. The addition of LFS significantly reduced the charge transfer resistance of the anode, substantially extending the cycle life and discharge capacity of commercial LFP/Gr pouch cells at -10 and -30 °C. Compared with the capacity retention rate of the baseline electrolyte at -10 °C (80 % after 25cycles), the capacity retention rate of the LFS electrolyte after 100 cycles under 0.5 C/0.5 C was retained at 94 %. Further mechanistic studies showed that the LFS additive induced the formation of a solid electrolyte interphase (SEI) film comprising inorganic-rich LiF, Li2SO4, and additional organic fluorides and sulfides to maintain good stability at the Gr/electrolyte interface during low-temperature operation. LFS suppressed electrolyte decomposition by forming a robust and low-resistance SEI film on the anode. These results demonstrate that LFS is a promising electrolyte additive for low-temperature LFP/Gr pouch cells.

Molecular-Enhanced Raman Spectroscopy Driven by Phosphoester Electron-Transfer Bridge.

Although both electromagnetic and charge transfer (CT) mechanisms play a role in surface-enhanced Raman scattering (SERS), the contribution of the latter is limited by poor CT efficiency. Herein, we propose molecular-enhanced Raman spectroscopy (MERS) for the first time and develop a simple strategy to induce strong CT-enhanced Raman signals using a phosphoester (POE) electron-transfer bridge. Consequently, an excellent POE-enhanced Raman effect was found when various mono-, bis-, and trisaminobenzene compounds were used as probe analytes. Quantification analysis of this MERS effect revealed that the enhancement ratio and factor of the POE molecules can be up to 87% and ∼109, respectively. Spectroscopic analysis and density functional theory calculation confirmed that this effect was because of the formation of intermolecular hydrogen bonds, which promotes CT via electronic reorganization and enhances the Raman signals of target analytes. These results demonstrate the feasibility of MERS for highly CT-enhanced Raman signals.

Ice-Template-Induced Highly Interconnected Porous Polymer Gel Electrolytes for Dendrite-Free Flexible Zinc-Air Batteries.

Improving the performance of quasi-solid-state gel polymer electrolytes is critical for addressing issues at the Zn anode-electrolyte interface of high-performance flexible Zn-air batteries (FZABs). In this study, a highly interconnected porous poly(vinyl alcohol)/poly(ethylene glycol) (PVA/PEG) hydrogel electrolyte was fabricated via an ice-crystal template for FZABs. The mechanical toughness and stability of the gel electrolytes can be reinforced by the formation of a PEG-PVA cross-linking network. The three-dimensional PVA/PEG porous skeleton greatly increased electrolyte uptake and accelerated ion transport, leading to high ionic conductivity (42.5 mS cm-1). In-situ synchrotron radiation X-ray imaging revealed that the PVA/PEG network can effectively inhibit dendrite growth and the hydrogen evolution reaction. The assembled FZABs exhibited superior cycle stability, high power density (109 mW cm-3), and excellent flexibility and structural stability under bending conditions, thus showing great potential for future applications in flexible and wearable electronic device technologies.

Modified LIX®84I-Based Polymer Inclusion Membranes for Facilitating the Transport Flux of Cu(II) and Variations of Their Physical-Chemical Characteristics.

A unique facilitation on the transport flux of Cu(II) was investigated by using modified polymer inclusion membranes (PIMs). LIX®84I-based polymer inclusion membranes (LIX®-based PIMs) using poly(vinyl chloride) (PVC) as support, 2-nitrophenyl octyl ether (NPOE) as plasticizer and Lix84I as carrier were modified by reagents with different polar groups. The modified LIX®-based PIMs showed an increasing transport flux of Cu(II) with the help of ethanol or Versatic acid 10 modifiers. The metal fluxes with the modified LIX®-based PIMs were observed varying with the amount of modifiers, and the transmission time was cut by half for the modified LIX®-based PIM cast with Versatic acid 10. The physical-chemical characteristics of the prepared blank PIMs with different Versatic acid 10 were further characterized by using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), contract angle measurements and electro-chemical impedance spectroscopy (EIS). The characterization results indicated that the modified LIX®-based PIMs cast with Versatic acid 10 appeared to be more hydrophilic with increasing membrane dielectric constant and electrical conductivity that allowed better accessibility of Cu(II) across PIMs. Hence, it was deduced that hydrophilic modification might be a potential method to improve the transport flux of the PIM system.

Chelate-Capped Nano-AgZn3 Dual Interphase Remodeling the Local Environment for Reversible Dendrite-Free Zinc Anode.

Rechargeable aqueous zinc-ion batteries (AZIBs) are among the most promising candidates for next-generation energy-storage devices. However, the large voltage polarisation and infamous dendrite growth hinder the practical application of AZIBs owing to their complex interfacial electrochemical environment. In this study, a hydrophobic zinc chelate-capped nano-silver (HZC-Ag) dual interphase is fabricated on the zinc anode surface using an emulsion-replacement strategy. The multifunctional HZC-Ag layer remodels the local electrochemical environment by facilitating the pre-enrichment and de-solvation of zinc ions and inducing homogeneous zinc nucleation, thus resulting in reversible dendrite-free zinc anodes. The zinc deposition mechanism on the HZC-Ag interphase is elucidated by density functional theory (DFT) calculations, dual-field simulations, and in situ synchrotron X-ray radiation imaging. The HZC-Ag@Zn anode exhibited superior dendrite-free zinc stripping/plating performance and an excellent lifespan of >2000 h with ultra-low polarisation of ≈17 mV at 0.5 mA cm-2 . Full cells coupled with a MnO2 cathode showed significant self-discharge inhibition, excellent rate performance, and improved cycling stability for >1000 cycles. Therefore, this multifunctional dual interphase may contribute to the design and development of dendrite-free anodes for high-performance aqueous metal-based batteries.

Aerophilic Triphase Interface Tuned by Carbon Dots Driving Durable and Flexible Rechargeable Zn-Air Batteries.

Efficient bifunctional catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are vital for rechargeable Zn-air batteries (ZABs). Herein, an oxygen-respirable sponge-like Co@C-O-Cs catalyst with oxygen-rich active sites was designed and constructed for both ORR and OER by a facile carbon dot-assisted strategy. The aerophilic triphase interface of Co@C-O-Cs cathode efficiently boosts oxygen diffusion and transfer. The theoretical calculations and experimental studies revealed that the Co-C-COC active sites can redistribute the local charge density and lower the reaction energy barrier. The Co@C-O-Cs catalyst displays superior bifunctional catalytic activities with a half-wave potential of 0.82 V for ORR and an ultralow overpotential of 294 mV at 10 mA cm-2 for OER. Moreover, it can drive the liquid ZABs with high peak power density (106.4 mW cm-2), specific capacity (720.7 mAh g-1), outstanding long-term cycle stability (over 750 cycles at 10 mA cm-2), and exhibits excellent feasibility in flexible all-solid-state ZABs. These findings provide new insights into the rational design of efficient bifunctional oxygen catalysts in rechargeable metal-air batteries.

Interfacial-Shear-Mediated Snowball Assembly of Hotspot-Rich Silver Pompon Architectures for Tailored Surface-Enhanced Raman Scattering Responses.

To gain superior signal-enhanced performance, metal nanocrystals serving as building blocks can be collectively assembled into a hierarchically ordered structure for creating multiple hotspots. However, the collaborative assembly of anisotropic crystals to form a hotspot-rich structure remains a challenging task. In this study, controllable shear was introduced to a soft liquid-liquid interface to provide a unique environment for the snowball assembly of silver pompon architectures (Ag-PAs). Micrometer-scale 3D plasmonic Ag pompon architectures composed of densely packed nanoparticles (NPs) are fabricated using shear-mediating crystal growth dynamics. The crystal morphology and size are easily controlled by tuning the interfacial shear and diffusion pathways. The hotspot-rich Ag-PAs with high sensitivity (LOD = 1.1 × 10-13 mol/L) exhibit a superior Raman enhancement performance, which is comparable to some bimetals.

Hydrophobic plasmonic silver membrane as SERS-active catcher for rapid and ultrasensitive Cu(II) detection.

The rapid and selective identification of heavy metal ions is crucial for environmental water safety. In this study, a novel surface-enhanced Raman scattering (SERS)-active catcher was designed for Cu(II) detection using a hydrophobic hydroxyoxime-mediated plasmonic silver membrane (HOX@Ag-PVDF). Uniformly dispersed Ag nanoparticles (ca. 80 nm) and hydroxyoxime molecules were synchronously decorated on the skeleton of the polyvinylidene fluoride membrane via an in situ interfacial assembly strategy. HOX@Ag-PVDF shows excellent SERS activity (EF = 2.5 × 107), high reproducibility (~8% RSD), and long-term stability (50 days) for detecting 4-nitrothiophenol (4-NTP). Moreover, HOX@Ag-PVDF can serve as a new platform for rapid and dry-free SERS detection of Cu(II) owing to its strong affinity and surface hydrophobicity. Cu(II) ions can be rapidly captured in 5 s and selectively recognized by SERS signals without interference from other metal ions. HOX@Ag-PVDF exhibits linear SERS response signals at low concentrations ranging from 10-6 to 10-10 mol/L Cu(II) (R2 = 0.9893) with a low detection limit (LOD) of 52.0 pmol/L. This hydrophobic plasmonic membrane, with its simple sampling and rapid SERS response characteristics, provides ultrasensitive recognition and heavy metal detection for practical applications.

Trace tea polyphenols enabling reversible dendrite-free zinc anode.

Zinc ion batteries (ZIBs) suffer from severe corrosion effects and dendrite growth on the unstable anode/electrolyte interface (AEI) during the plating/stripping process. Therefore, it is of great significance to build a stable AEI enabling a long lifetime for ZIBs. Herein, trace tea polyphenols (TP) were introduced firstly as additive of zinc acetate electrolyte to protect zinc anode from corrosion invasion and boost uniform zinc deposition, thus achieving reversible dendrite-free zinc anode. In situ synchrotron radiation X-ray imaging was conducted to illustrate the positive role of TP molecules in the uniform plating process of zinc. The stable AEI induced by the specific adsorption of TP molecules reduced hydrogen and oxygen evolution side reactions and increased the coulombic efficiency. The TP additive with an ultralow dosage of 0.028 g L-1 delivered favorable cycling stability of 720 h at 0.5 mA cm-2 and 0.5 mAh cm-2. The Zn-Na3V2(PO4)3 full cell assembled with the hybrid Zn(Ac)2-TP electrolyte contributed an energy density of 130 mAh g-1 at the current density of 0.2C and enhanced cycling stability of 78% retention after 300 cycles. These results will provide new insights into additive engineering for aqueous electrolytes and the fundamental understanding of AEI phenomena for high performance ZIBs.

Ultra-Low-Dose Pre-Metallation Strategy Served for Commercial Metal-Ion Capacitors.

HIGHLIGHTS: Interfacial bonding strategy has been successfully applied to address the high overpotential issue of sacrificial additives, which reduced the decompositon potential of Na2C2O4 from 4.50 to 3.95 V. Ultra-low-dose technique assisted commercial sodium ion capacitor (AC//HC) could deliver a remarkable energy density of 118.2 Wh kg-1 as well as excellent cycle stability. In-depth decomposition mechanism of sacrificial compound and the relative influence after pre-metallation were revealed by advanced in situ and ex situ characterization approaches. Sacrificial pre-metallation strategy could compensate for the irreversible consumption of metal ions and reduce the potential of anode, thereby elevating the cycle performance as well as open-circuit voltage for full metal ion capacitors (MICs). However, suffered from massive-dosage abuse, exorbitant decomposition potential, and side effects of decomposition residue, the wide application of sacrificial approach was restricted. Herein, assisted with density functional theory calculations, strongly coupled interface (M-O-C, M = Li/Na/K) and electron donating group have been put forward to regulate the band gap and highest occupied molecular orbital level of metal oxalate (M2C2O4), reducing polarization phenomenon and Gibbs free energy required for decomposition, which eventually decrease the practical decomposition potential from 4.50 to 3.95 V. Remarkably, full sodium ion capacitors constituted of commercial materials (activated carbon//hard carbon) could deliver a prominent energy density of 118.2 Wh kg-1 as well as excellent cycle stability under an ultra-low dosage pre-sodiation reagent of 15-30 wt% (far less than currently 100 wt%). Noteworthily, decomposition mechanism of sacrificial compound and the relative influence on the system of MICs after pre-metallation were initially revealed by in situ differential electrochemical mass spectrometry, offering in-depth insights for comprehending the function of cathode additives. In addition, this breakthrough has been successfully utilized in high performance lithium/potassium ion capacitors with Li2C2O4/K2C2O4 as pre-metallation reagent, which will convincingly promote the commercialization of MICs.

Coupling regeneration strategy of lithium-ion electrode materials turned with naphthalenedisulfonic acid.

The resource exhaustion and environmental assessment driven by sustainable development make recycle of spent LIBs urgent to be achieved. However, the conventional recycling processes are quite complicated in terms of the tedious steps and secondary contamination. In this paper, hydrosoluble naphthalenedisulfonic acid is firstly proposed to selectively extract valuable metals (Co and Li) for the regeneration of battery materials. Lithium is selectively recovered as lithium enriched solution with a high yield of 99%, while 96.6% cobalt remains in a complex-precipitate benefited from the high acidity and coordination role of naphthalenedisulfonic acid. The leaching of Li fits well with the logarithmic rate law model with an activation energy of 32.42 kJ/mol. Additionally, the regenerated lithium-ion battery active materials (Co3O4 anode and LiCoO2 cathode) prepared from the cobalt complex-precipitate and lithium-enriched solution exhibit excellent discharged-charged performances and rate capability. This feasible strategy assisted by multifunctional naphthalenedisulfonic acid may offer an alternative option for the simultaneous recovery of Li and Co and the rational resource utilization of spent lithium-ion batteries.

Highly efficient re-cycle/generation of LiCoO2 cathode assisted by 2-naphthalenesulfonic acid.

The explosively growing demand for electrical energy is generating a great deal of spent lithium-ion batteries (LIBs). Therefore, a simple and effective strategy for the sustainable recycling of used batteries is urgently needed to minimize chemical consumption and to reduce the associated environmental pollution. In this work, 2-naphthalenesulfonic acid is innovatively proposed for the highly-selective recovery of valuable metals. Impressively, lithium and cobalt are simultaneously separated through a single-step process, in which 99.3% of lithium is leached out as Li+ enriched solutions while 99% of cobalt is precipitated as cobalt-naphthalenesulfonate. The obtained lithium enriched solutions are recovered as Li2CO3. The cobalt-naphthalenesulfonate with high purity (99%) is ready to be transformed into Co3O4, and then generated into LiCoO2 by reacting with the above-obtained Li2CO3. The cathode material LiCoO2 with micro/nanostructures exhibits excellent electrochemical properties. Characterization results confirm the coordination structure of the extracted cobalt complex (Co(NS)2•6H2O). Finally, compared to other selective metal extraction techniques, this strategy avoids additional separation and purification processes, thus improving the recycling efficiency. Overall, this route can be extended to selectively extract valuable metals from other types of cathode materials in spent LIBs as a sustainable approach.

Electrochemically Engineering Antimony Interspersed on Graphene toward Advanced Sodium-Storage Anodes.

Nanoengineering of metal anode materials shows great potential for energy storage with high capacity. Zero-dimensional nanoparticles are conducive to acquire remarkable electrochemical properties in sodium-ion batteries (SIBs) because of their enlarged surface active sites. However, it is still difficult to fulfill the requirements of practical applications in batteries owing to the deficiency of efficient and scalable preparation approaches of high-performance metal electrode materials. Herein, an electrochemical cathodic corrosion method is proposed for the tunable preparation of nanostructured antimony (Sb) by the introduction of a surfactant, which can efficiently avoid the agglomeration of Sb atom clusters generated from the Zintl compound and further stacking into bulk during the electrochemical process. Subsequently, graphene as the support and conductive matrix is uniformly interspersed by generating Sb nanoparticles (Sb/Gr). Moreover, the reversible crystalline-phase evolution of Sb ⇋ NaSb ⇋Na3Sb for Sb/Gr was studied by in situ X-ray diffraction (XRD). Benefiting from the interconnection of the conductive network, Sb/Gr anodes deliver a high capacity of 635.34 mAh g-1, a retained capacity of 507.2 mAh g-1 after 150 cycles at 0.1 C (1 C = 660 mAh g-1), and excellent rate performance with the capacities of 473.41 and 405.09 mAh g-1 at 2 and 5 C, respectively. The superior cycle stability with a capacity of 346.26 mAh g-1 is achieved after 500 cycles at 2 C. This electrochemical approach offers a new route toward developing metal anodes with designed nanostructures for high-performance SIBs.

Coral-like carbon-wrapped NiCo alloys derived by emulsion aggregation strategy for efficient oxygen evolution reaction.

The transition metal-based catalysts have great potential to boost the electrocatalytic reactions due to their flexible electronic configuration and low cost. This work developed a facile emulsion aggregation strategy to synthesize coral-like carbon-wrapped NiCo alloy (Co0.5Ni0.5/rGO) with high oxygen evolution reaction (OER) activity. The effect of alloy composition and GO content on the OER activity was evaluated in the 1 mol L-1 KOH solution. The OER mechanism of the Co0.5Ni0.5/rGO catalyst was disclosed by X-ray photoelectron spectra (XPS) and synchrotron radiation X-ray absorption spectra (XAS). The emulsion containing amphipathic graphene oxide (GO) and hydrophobic nickel/cobalt complexes induces the formation of the carbon-wrapped nanostructure. The coral-like Co0.5Ni0.5/rGO catalyst exhibits the low overpotential of 288 mV at the current density of 10 mA cm-2 and good durability, both of which are superior to the standard RuO2. The synergistic effect between nickel and cobalt effectively regulates the electronic structure and OER activity of the alloy catalysts. Moreover, the interaction between NiCo alloys and carbon shells can reduce the interfacial resistance.

Ultra-stable Sb confined into N-doped carbon fibers anodes for high-performance potassium-ion batteries.

Antimony-based materials with high theoretical capacity are known as promising anodes for potassium-ion batteries (PIBs). However, they still face challenges from the large ionic radius of the K ion, which has sluggish kinetics. Much effort is needed to exploit high-performance electrode materials to satisfy the reversible capacity of PIBs. In this paper, nano Sb confined in N-doped carbon fibers (Sb@CN nanofibers) were successfully prepared through an electrospinning method, which was designed to improve potassium storage performances. Sb@CN nanofibers benefit from the fact that the synergy between the porous nanofiber frame structure and the uniformly distributed Sb nano-components in the carbon matrix can effectively accelerate the ion migration rate and reduce the mechanical stress caused by K+ insertion/extraction, Sb@CN nanofiber electrodes thus exhibited excellent potassium storage performance, especially long cycle stability, as expected. When utilized as a PIB anode, they delivered high reversible capacity of 360.2 mAh g-1 after 200 cycles at 50 mA g-1, and a particularly stable capacity of 212.7 mAh g-1 was also obtained after 1000 cycles even at 5000 mA g-1. Given such outstanding electrochemical performances, this work is expected to provide insight into the development and exploration of advanced alloy-type electrodes for PIBs.

Oxygen Vacancy-Rich In-Doped CoO/CoP Heterostructure as an Effective Air Cathode for Rechargeable Zn-Air Batteries.

An efficient and low-cost electrocatalyst for reversible oxygen electrocatalysis is crucial for improving the performance of rechargeable metal-air batteries. Herein, a novel oxygen vacancy-rich 2D porous In-doped CoO/CoP heterostructure (In-CoO/CoP FNS) is designed and developed by a facile free radicals-induced strategy as an effective bifunctional electrocatalyst for rechargeable Zn-air batteries. The electron spin resonance and X-ray absorption near edge spectroscopy provide clear evidence that abundant oxygen vacancies are formed in the interface of In-CoO/CoP FNS. Owing to abundant oxygen vacancies, porous heterostructure, and multiple components, In-CoO/CoP FNS exhibits excellent oxygen reduction reaction activity with a positive half-wave potential of 0.81 V and superior oxygen evolution reaction activity with a low overpotential of 365 mV at 10 mA cm-2 . Moreover, a home-made Zn-air battery with In-CoO/CoP FNS as an air cathode delivers a large power density of 139.4 mW cm-2 , a high energy density of 938 Wh kgZn -1 , and can be steadily cycled over 130 h at 10 mA cm-2 , demonstrating great application potential in rechargeable metal-air batteries.

Molecular-Level CuS@S Hybrid Nanosheets Constructed by Mineral Chemistry for Energy Storage Systems.

The transition-metal sulfide, CuS, is deemed a promising material for energy storage, mainly derived from its good chemisorption and conductivity, although serious capacity fading limits its advancement within reversible lithium storage. Learning from the gold extraction method utilizing the lime-sulfur-synthetic-solution, a CuS@S hybrid utilizing CaS x as both sulfur resource and reductant-oxidant is prepared, which is an efficient approach to apply the metallurgy for the preparation of electrode materials. Regulating the amount of CuCl2, the CuS@S is induced to reach a molecular-level hybrid. When utilized as an anode within a lithium-ion battery, it presents the specific capacity of 514.4 mA h g-1 at 0.1 A g-1 over 200 cycles. Supported by the analyses of pseudo-capacitive behaviors, it is confirmed that the CuS matrix with the suitable content of auxiliary sulfur could improve the durability of the CuS-based anode. Expanding the wider application within lithium-sulfur batteries, the synchronous growth of CuS@S exhibits stronger chemisorption with polysulfides than the mechanical mixture of CuS and S. A suite of in situ electrochemical impedance spectroscopy studies further investigates the stable resistances of the CuS@S within the charge/discharge process, corresponding to the reversible structure evolution. This systematic work may provide a practical fabricating route of metal sulfides for scalable energy storage applications.

Real-Time X-ray Imaging Reveals Interfacial Growth, Suppression, and Dissolution of Zinc Dendrites Dependent on Anions of Ionic Liquid Additives for Rechargeable Battery Applications.

The dynamic interfacial growth, suppression, and dissolution of zinc dendrites have been studied with the imidazolium ionic liquids (ILs) as additives on the basis of in situ synchrotron radiation X-ray imaging. The phase contrast difference of real-time images indicates that zinc dendrites are preferentially developed on the substrate surface in the ammoniacal electrolytes. After adding imidazolium ILs, both nucleation overpotential and polarization extent increase in the order of additive-free < EMI-Cl < EMI-PF6 < EMI-TFSA < EMI-DCA. The real-time X-ray images show that the EMI-Cl can suppress zinc dendrites, but result in the formation of the loose deposits. The EMI-PF6 and EMI-TFSA additives can smooth the deposit morphology through suppressing the initiation and growth of dendritic zinc. The addition of EMI-DCA increases the number of dendrite initiation sites, whereas it decreases the growth rate of dendrites. Furthermore, the dissolution behaviors of zinc deposits are compared. The zinc dendrites show a slow dissolution process in the additive-free electrolyte, whereas zinc deposits are easily detached from the substrate in the presence of EMI-Cl, EMI-PF6, or EMI-TFSA due to the formation of the loose structure. Hence, the dependence of zinc dendrites on anions of imidazolium IL additives during both electrodeposition and dissolution processes has been elucidated. These results could provide the valuable information in perfecting the performance of zinc-based rechargeable batteries.

Microscopic insights into extraction mechanism of copper(II) in ammoniacal solutions studied by X-ray absorption spectroscopy and density functional theory calculation.

A microscopic investigation on the extraction process of copper(II) in ammoniacal solutions has been performed by X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculation. The structural change of copper(II) species in ammoniacal solution has been derived from X-ray absorption near-edge spectroscopy (XANES) by principal component analysis and linear combination fitting. It was found that the coordination structure of the extracted copper complex in the organic phases is planar square and independent of the aqueous pH, whereas the geometries of copper(II) species in ammoniacal solutions changed from axially elongated octahedron to distorted planar square with increase of pH. The coordination geometry and structural parameters of copper(II) species were further obtained by extended X-ray absorption fine structure (EXAFS) fitting and DFT calculation with the B3LYP functional. These results reveal that the formation of tetracoordinated copper(II) ammine species can evidently inhibit the copper extraction reaction. Thus, the extraction mechanism of copper(II) in ammoniacal solutions has been elucidated in view of the microscopic structural aspects of copper species in both organic phase and ammoniacal solutions.