Inert Electrode Research Articles

Ab Initio Kinetics of Electrochemical Reactions Using the Computational Fc0/Fc+ Electrode.

The current state-of-the-art electron-transfer modeling primarily focuses on the kinetics of charge transfer between an electroactive species and an inert electrode. Experimental studies have revealed that the existing Butler-Volmer model fails to satisfactorily replicate experimental voltammetry results for both solution-based and surface-bound redox couples. Consequently, experimentalists lack an accurate tool for predicting electron-transfer kinetics. In response to this challenge, we developed a density functional theory-based approach for accurately predicting current peak potentials by using the Marcus-Hush model. Through extensive cyclic voltammetry simulations, we conducted a thorough exploration that offers valuable insights for conducting well-informed studies in the field of electrochemistry.

Engineered stable electron-doping water with higher chemical activity catalyzes itself in hydrogen evolution reactions

Additional huge amount of energy is required for water splitting due to strong surrounding hydrogen bonds (HBs) between water molecules. However, this underappreciated fact has not attracted the attention of scientists to shift to the research direction to the reactant water itself in hydrogen evolution reactions (HERs). In this work, we report a facile cold water-cooling method to prepare distilled water (DIW-V) with distinct structures of electron-doping and reduced HBs. Compared to bulk deionized water (DIW) which was used to prepare DIW-V, the resulting stable DIW-V exhibited distinct properties at room temperature. Examples are its ability to scavenge 2,2-diphenyl-1-picrylhydrazyl free radicals and to passivate oxidants of H2O2 through utilizing its novel electron-doping structure. Also, typical electrochemical reactions performed in DIW-V were more efficient, and stronger intermolecular HBs between alcohols and DIW-V were exhibited due to its novel reduced HBs. Moreover, HERs performed on both catalytic and inert electrodes at various pH values were all more efficient when utilizing DIW-V. Experiments regarding density measurements of alcohol solutions and HER performances indicated that stabilities of the activities of DIW-V were acceptable. DIW-V was also available for more efficient oxygen evolution reaction utilizing catalytic Pt electrode in favorable alkaline solution. Our proposed DIW-V has emerged as a promising green and active reactant applicable to more-effective HERs and water-related sciences.

α-CsPbI3 Quantum Dots ReRAM with High Air Stability Working by Valance Change Filamentary Mechanism.

The current memory system is facing obstacles to improvement, and ReRAM is considered a powerful alternative. All-inorganic α-CsPbI3 perovskite-based ReRAM working by electrochemical mechanism is reported, but the electrochemically active electrode raised difficulty in long-term stable operation, and bulk α-CsPbI3 device can not show resistive switching behavior with an inert metal top electrode. Herein, by making the α-CsPbI3 into QDs and applying it to the device with inert Au as the top electrode, the devices working by valence change mechanism are successfully fabricated. The large surface-to-volume ratio made an abundant amount of iodine vacancies and facile migration of vacancies allowed the device to work by valence change mechanism. The devices show reliable electrical characteristics, 800 cycles endurance and retention for over 4 × 104 s, and air stability for 1 month. This work demonstrates that applying the QDs can improve the stability and enable a new type of working mechanism in ReRAM.

Impact of inert electrode on the volatility and non-volatility switching behavior of SiO2-based conductive bridge random access memory devices

Impact of inert electrode on the volatility and non-volatility switching behavior of SiO2-based conductive bridge random access memory devices

Electrochemical behavior and separation of ytterbium from NaCl-CaCl2 molten salt by reactive electrodes

To electro-extract Yb from NaCl–CaCl2 molten salt, the electrochemical behavior of Yb(III) was studied by cyclic voltammetry (CV), square wave voltammetry (SWV), chronopotentiometry (CP) and open circuit chronopotentiometry (OCP) on inert Mo and reactive Ni and Cu electrodes in NaCl–CaCl2 molten salt at 923 K. It was found that Yb(III) was reduced to Yb(II) on the Mo electrode and no Yb metal was formed prior to the reduction of Na+/Ca2+ ions, suggesting that the electroreduction of Yb(II) to Yb on inert Mo electrode is impossible. The diffusion coefficient of Yb(III) was determined by CV and CP and the results by the two methods showed good consistency. However, the reduction peaks of four Ni-Yb and five Cu-Yb intermetallic compounds were formed on reactive electrodes Ni and Cu, respectively. Thus, the reduction of Yb(II)/Yb became possible by this cathodic alloying method. To investigate the feasibility of the separation of ytterbium from this molten salt, potentiostatic electrolysis were carried out at −1.83 V, −2.0 V, −2.2 V, and −2.4 V (vs. Ag/AgCl) respectively on the Ni electrode and at −2.1 V (vs. Ag/AgCl) on the Cu electrode. The results showed that the yield of Yb atoms in the electrolytic alloy layer becomes higher when the applied potential shifts negatively, and Ni electrode is confirmed more suitable than Cu material for Yb separation in NaCl–CaCl2 molten salt.

Tuning Stainless Steel Oxide Layers through Potential Cycling─AEM Water Electrolysis Free of Critical Raw Materials.

Anion exchange membrane water electrolyzers (AEMWEs) have an intrinsic advantage over acidic proton exchange membrane water electrolyzers through their ability to use inexpensive, stable materials such as stainless steel (SS) to catalyze the sluggish oxygen evolution reaction (OER). As such, the study of active oxide layers on SS has garnered great interest. Potential cycling is a means to create such active oxide layers in situ as they are readily formed in alkaline solutions when exposed to elevated potentials. Cycling conditions in the literature are rife with unexplained variations, and a complete account of how these variations affect the activity and constitution of SS oxide layers remains unreported, along with their influence on AEMWE performance. In this paper, we seek to fill this gap in the literature by strategically cycling SS felt (SSF) electrodes under different scan rates and ranges. The SSF anodes were rapidly activated within the first 50 cycles, as shown by the 10-fold decline in charge transfer resistance, and the subsequent 1000 cycles tuned the metal oxide surface composition. Cycling the Ni redox couple (RC) increases Ni content, which is further enhanced by lowering the cycling rate, while cycling the Fe RC increases Cr content. Fair OER activity was uncovered through cycling the Ni RC, while Fe cycling produced SSF electrodes active toward both the OER and the hydrogen evolution reaction (HER). This indicates that inert SSF electrodes can be activated to become efficient OER and HER electrodes. To this effect, a single-cell AEMWE without any traditional catalyst or ionomer generated 1.0 A cm-2 at 1.94 V ± 13.3 mV with an SSF anode, showing a fair performance for a cell free of critical raw materials.

Fabrication perspective of Fe3O4-based cross-cell memristive device for synaptic applications

Neurotransmitter release in chemical synapses plays a pivotal role in a wide range of essential brain functions, including neural activity (potentiation/depression), learning, cognition, emotion, perception, and consciousness. In this study, we have presented the fabricated cross-cell memristive device that exhibits an analog resistive switching (ARS) device, with Silver (Ag) as active and Platinum (Pt) as inert metal electrodes. The energy bandgap, crystal structure, surface morphology, elemental composition, and electronic properties of the deposited metal-oxide thin film were examined by using UV–Vis spectroscopy, Glancing Angle X-ray diffraction (GAXRD), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX), and Raman spectroscopy, respectively. The electrical characteristics of the fabricated resistive switching (RS) device have been studied by the Keithley 4200A SCS parameter analyzer by low triangular DC sweep voltage (-2V/+2V) at room temperature (RT). Furthermore, we have evaluated the outstanding performance of the fabricated cross-cell RS device at a read voltage of 0.1V, and we have also discussed its remarkable linearity. This work will aid researchers in realizing the synaptic behavior of cross-cell devices for neuromorphic computing applications.

Electrochemical behavior and effective extraction of Er in fused LiCl-KCl eutectic

For the efficient electrolytic extraction of Er from spent nuclear fuel, a series of electrochemical methods was used to research the electrochemical behavior of Er(III) in the LiCl-KCl system on inert (Mo) electrode and on reactive (Ni) electrodes. On the inert Mo electrode, the reduction of Er(III) to Er(0) is a one-step with three-electron and quasi-reversible reaction process. Meanwhile, the apparent generation Gibbs free energy and activity coefficients of Er(III) on the inert electrode were determined. Thereafter, the electrochemical reduction of Er(III) on the Ni electrode was emphatically investigated. Er(III) is reduced at a corrected potential owing to the formation of Ni-Er alloys. In addition, thermodynamic parameters such as partial excess Gibbs free energy change of Er in Ni, activity and apparent generation Gibbs free energy of the Ni-Er alloys were determined by the electromotive force method. Finally, different Ni-Er alloys were produced using potentiostatic electrolysis on the Ni cathode by controlling different potentials. Moreover, electrolytic extraction was carried out on the Ni cathode at the potential of –2.0 V, and the separation efficiency of Er reaches 99.72%, which proves the practicability of separating Er from LiCl-KCl eutectic on the reactive Ni cathode.

Electrochemistry of Uranium on Liquid Cadmium Electrode in LiCl-KCl Eutectic

This work presents the electrochemical study of LiCl-KCl-UCl3 solutions at the temperature range 673–823 K on inert and reactive electrodes, i.e. W and Cd, respectively. On inert electrode, U(III) ions were reduced to metallic uranium through one step and the mechanism of the cathode reaction was irreversible. The diffusion coefficients of U(III) ions in molten chloride eutectic and liquid cadmium were calculated. On reactive electrode, U(III) ions were reduced with depolarization and were accompanied by the formation of intermetallic compound UCd11. The reactions of the cathodic deposition and anodic dissolution of the U-Cd alloy were studied and the conditions of the alloy formation via galvanostatic electrolysis were found. The solubility and the activity of uranium in liquid cadmium were determined.

Synthesis of bimetal-decorated N-doped carbon nanoparticles for enhanced oxygen evolution reaction

Electrochemical hydrogen generation from the most plausible splitting water is severely hindered by OER (oxygen evolution reaction). Hence, the Fe4Co6@NDC amorphous sheet-like lamellar potential electrocatalyst prepared through simple solvothermal synthesis towards OER with low overpotential 307 mV @ 10 mA cm−2, Tafel slope of −55 mV dec-1 and turnover frequency of 0.0396 s−1, compared to 393 mV, Tafel slope of −81 mV dec-1, and a turnover frequency of 0.0136 s−1 at an IrO2 on an inert glassy carbon electrode, under the same conditions in 1 M KOH. The iron: cobalt adjacent ratio (4:6) could give a cooperative synergistic effect for OER, further nitrogen-doped carbon substrate (NDC) offers even metal anchoring sites has provided higher ECSA of 10.202 cm2 and also provides low resistive (5.6 Ω) material. Full cell water splitting Fe4Co6@NDC/NF (anode)//PtC/NF (cathode) with cell potential 1.58 V and the same setup will be used with perennial solar energy source only consumes 1.57 V enhanced hydrogen generation. We anticipate that the developed Fe4Co6@NDC electrocatalyst will be used as a formidable OER catalyst for a clean electrochemical energy conversion process.

Ion-Selective Potentiometry with Plasma-Initiated Covalent Attachment of Sensing Membranes onto Inert Polymeric Substrates and Carbon Solid Contacts.

The physical delamination of the sensing membrane from underlying electrode bodies and electron conductors limits sensor lifetimes and long-term monitoring with ion-selective electrodes (ISEs). To address this problem, we developed two plasma-initiated graft polymerization methods that attach ionophore-doped polymethacrylate sensing membranes covalently to high-surface-area carbons that serve as the conducting solid contact as well as to polypropylene, poly(ethylene-co-tetrafluoroethylene), and polyurethane as the inert polymeric electrode body materials. The first strategy consists of depositing the precursor solution for the preparation of the sensing membranes onto the platform substrates with the solid contact carbon, followed by exposure to an argon plasma, which results in surface-grafting of the in situ polymerized sensing membrane. Using the second strategy, the polymeric platform substrate is pretreated with argon plasma and subsequently exposed to ambient oxygen, forming hydroperoxide groups on the surface. Those functionalities are then used for the initiation of photoinitiated graft polymerization of the sensing membrane. Attenuated total reflection-Fourier transform infrared spectroscopy, water contact angle measurements, and delamination tests confirm the covalent attachment of the in situ polymerized sensing membranes onto the polymeric substrates. Using membrane precursor solutions comprising, in addition to decyl methacrylate and a cross-linker, also 2-(diisopropylamino)ethyl methacrylate as a covalently attachable H+ ionophore and tetrakis(pentafluorophenyl)borate as ionic sites, both plasma-based fabrication methods produced electrodes that responded to pH in a Nernstian fashion, with the high selectivity expected for ionophore-based ISEs.

Исследование механизма совместного электровосстановления ионов Dy3+ и Co2+ в эвтектическом расплаве KCl-NaCl-CsCl при 823 К

The kinetic patterns of the electroreduction of the Co2+ ion in the eutectic melt KCl-NaCl-CsCl at 823 K have been determined. It has been established that the release potentials of metallic cobalt and dysprosium on an inert tungsten electrode in the molten KCl-NaCl-CsCl system differ by approximately 1.5 V. It has been shown that with the combined content of Co2+ and Dy3+ ions in the eutectic KCl-NaCl-CsCl melt, a certain depolarization of the electroreduction of dysprosium ions takes place on the metal cobalt pre-precipitated on the tungsten electrode with the formation of intermetallic phases of different compositions based on cobalt and dysprosium. The dissolution potentials of DyxCoy intermetallic phases of different compositions were determined using switch-off chronopotentiometry.

Application of the synergistic Ti/SnO2–Sb–Cu anode and Ti/ZnO/CuO cathode in the electrochemical treatment of wastewater

The current research mostly focused on the single working electrode of anode for the treatment of wastewater. Therefore, a low-cost dual-electrode system using Ti/SnO2–Sb–Cu (TSSC) as the anode and Ti/ZnO/CuO (TZC) as the cathode was constructed for the synergistic treatment of methylene blue dye wastewater. Electrochemical analyses of the TSSC electrode show an ultra-high oxygen evolution potential of 2.2 V, the greater stability and the excellent corrosion resistance when compared with the traditional Ti/SnO2–Sb (TSS) electrodes. Hydroxyl radicals (•OH) are thought to be the main oxidants in the degradation process, the results show that the content of •OH of the TZC cathode is 57 % higher than that of ordinary inert electrode. Due to the synergistic effect of the two electrodes, the color of methylene blue can be quickly removed by 99 % in 20 min, and the highest chemical oxygen demand (COD) removal rate can reach 79.5 %. The optimal operation conditions were a pH of 4, a current density of 20 mA cm−2 and an initial concentration of 50 mg L−1. Finally, the degradation pathway of MB was investigated using GC-MS technique and UV absorption spectroscopy. The results suggest that the large organic molecules are continuously cleaved to produce simple aromatic hydrocarbons, which are then destroyed to simple minor organic molecules, ultimately oxidized to CO2 and H2O. This investigation suggests a new idea for the design of an efficient and cost-effective double electrode for the electrocatalytic degradation of dye wastewater.

Evaporating hydrovoltaics with asymmetric electrodes

Power generation through natural evaporation shows great potential for green energy technologies. However, it remains a great challenge to balance the coupling effect between the interfacial potential and streaming potential. Here, we propose a new evaporating-hydrovoltaic strategy with asymmetric electrodes to optimize the coupling effect. This device uses active electrode to enhance interfacial interactions while inert electrode to avoid mutual blocking of interfacial potentials. The polytetrafluoroethylene (PTFE) membrane acts as a conductive connection path and induces a streaming potential. It is found that configuration of C (inert electrode)- PTFE (positively charged porous material)-Cu (active electrode) along the water gradient, achieves the optimal power generation. Exposing such a centimeter-sized device to environmental condition can generate ∼0.36 V voltage and lasts for ∼10 h without significant changes. Such high performance is ascribed to the consistency of potential level between interfacial potential and streaming potential. The findings provide a general guideline for sustainable power generation based on a synergistic effect of interfacial potential and streaming potential, which has far-reaching implications to the future design of hydrovoltaics.

Electrochemical Behavior of Tris(2,2'-bipyridine)Iron Complex in 1-Butyl-1-Methylpyrrolidinium Bis(fluorosulfonyl)Amide Ionic Liquid in the Presence and Absence of Lithium Ion

Ionic liquids composed of bis(fluorosulfonyl)amide (FSA–) have been investigated as the promising electrolytes for rechargeable batteries because of the formation of favorable solid electrolyte interphase (SEI) for some alkali metal ions in addition to relatively low viscosity. The FSA–-based ionic liquids are also considered to be applied to redox flow batteries, which utilize the electrode reactions of soluble species on inert electrodes. However, few electrode reactions of dissolved species have been explored in the FSA–-based ionic liquids. On the other hand, ion-conductive membranes are necessary for development of redox flow batteries. An inorganic solid-state conductor, lithium ion conductive glass ceramics (LICGC, Li1+x+y Al x (Ti,Ge)2-x Si y P3-y O12), is one of the possible membranes usable in ionic liquids containing Li+. In the present study, the electrochemical behavior of tris(2,2'-bipyridine)iron complexes, [Fe(bpy)3]2+, was investigated in BMPFSA (BMP = 1-butyl-1-methylpyrrolidinium) in the presence and absence of Li+.The redox reactions of [Fe(bpy)3]3+/2+, [Fe(bpy)3]2+/+, [Fe(bpy)3]+/0, and [Fe(bpy)3]0/– were observed by cyclic voltammetry in the absence of Li+. However, these reactions were affected by the SEI formation at a negative potential region in the presence of Li+. The donor number of BMPFSA was estimated from the formal potential of [Fe(bpy)3]3+/2+. The diffusion coefficients of [Fe(bpy)3]3+ and [Fe(bpy)3]2+ were determined by chronoamperometry. The standard rate constant for [Fe(bpy)3]3+/2+ was evaluated by electrochemical impedance spectroscopy. The relationship between these kinetic parameters and physical properties was discussed.

Real-Time Mass Spectrometry for Simultaneous Monitoring of Electrode Dissolution and Reaction Product Distribution during Organic Electrosynthesis

An organic electrosynthesis is an emerging tool for modern chemical manufacturing fitting the environmental and sustainability agenda. It utilizes polarized electrode surfaces as “traceless” oxidants or reductants, whereas its heterogeneous nature and exceptional tunability enable easy access to radical intermediates and novel mechanistic pathways. In the line of further energy input improvement, there is a growing demand for appropriate catalytic materials devoted to organic molecule transformations, for which the activity and selectivity have so far been most studied. Although the investigation of electrodes’ and electrocatalysts’ stability in the field of electrochemical energy conversion is well-established, there is still a lack of attention to the symmetrical studies for organic electrosynthesis. Nevertheless, electrode material losses shorten the reactor’s lifetime and can cause metal cathodic re-depositions, severely altering reaction product selectivity and final product contaminations. Although some reports on the ex-cell metal dissolution analysis are available, no information about its mechanism can be gained in such a way. To highlight the issue numerically, an analytical method to characterize rates and mechanisms of catalyst dissolution within a real-time response-enabled potential-, temperature-, or time-resolved parametrization of the electrocatalyst is highly demanded.Herein we present a system to study organic electrosynthetic protocols under dynamic operations to quantitatively monitor the electrode dissolution aligned with reaction products during organic molecules transformations. The instrument comprises an electrochemical flow cell (EFC) with exchangeable working electrodes, the outlet of which is interfaced with an online quadrupole mass spectrometer (OQMS) for the analysis of extracted by solid membrane gaseous products and an inductively coupled plasma mass spectrometer (ICP-MS) for the detection of dissolved metals. The system is exemplified by a benchmark Kolbe electrolysis over platinum Pt anode, commonly considered a stable and inert electrode material. Based on the literature, methanol has been used as a solvent of choice, while partially neutralized acetic acids with different bases were studied as objects. The methodology shed some light on understanding the role of platinum oxide formation on the electrode surface and can be used to study time- and potential-resolved catalyst stability and the possibility for dissolved transition metal-catalyzed electroorganic transformations.

Experimental investigation and thermodynamic assessment of phase equilibria in the GaTe–AgGa5Te8–Te system below 600 K

Equilibrium T–x space of the Ag–Ga–Te system in the GaTe–AgGa5Te8–Te part was divided below 600 K into three-phase regions Ga2Te5–AgGa5Te8–Te, Ga2Te3–AgGa5Te8–Ga2Te5, Ga7Te10–AgGa5Te8–Ga2Te3, Ga3Te4–AgGa5Te8–Ga7Te10, and GaTe–AgGa5Te8–Ga3Te4 by the electromotive force (EMF) method. To accomplish accurate experimental data, the following electrochemical cells (ECs) were assembled: (−)IE|NE|SSЕ|R{Ag+}|PЕ|IE(+), where IE is the inert electrode (graphite powder), NE is the negative electrode (silver powder), SSE is the solid-state electrolyte (glassy Ag3GeS3Br), PE is the positive electrode, R{Ag+} is the region of PE that contact with SSE. At the stage of cell preparation, PE is a nonequilibrium phase mixture of the well-mixed powdered compounds Ag2Te, GaTe, Ga2Te3, and tellurium, taken in ratios corresponding to two or three different points in each of the mentioned regions. The equilibrium set of phases was formed in the R{Ag+} region at 600 K for 48 h with the participation of the Ag+ ions. Silver cations, displaced for thermodynamic reasons from the NE to the PE of the ECs, acted as catalyst, i.e., small nucleation centers of equilibrium phases. The spatial position of the established three-phase regions relative to the silver point was used to assign the overall potential-determining reactions of synthesis of the ternary AgGa5Te8 and binary Ga2Te5, Ga7Te10, Ga3Te4 compounds. For the first time, the values of the standard thermodynamic functions (Gibbs energies, enthalpies, and entropies) of these compounds were determined based on the temperature dependences of the EMF of the ECs.

Bipolar and rectifying resistive switching dynamics in E-beam evaporated SnOx based memristor

In this article, we have examined the crystallinity and semiconducting properties (n-type and/or p-type) of e-beam evaporated Tin-oxide (SnOx) with different deposition substrate temperature and study their impact over resistive switching dynamics with Silver (Ag) active and Platinum (Pt) inert metal electrode. The fabricated Resistive switching (RS) devices have performed forming free bipolar and rectifying resistive switching with n-type and p-type semiconducting properties of deposited insulating layer, respectively. The crystal structure and elemental composition of deposited insulating layers (SnOx) have been characterized by using Glancing Angel X-Ray Diffraction (GAXRD) and Energy Dispersive X-Ray (EDX). The electrical responses of fabricated RS devices have been observed by using Keithley-4200 parametric analyser with customize probe station and performance of the bipolar and rectifying RS devices have been analysed with low sweeping voltage (−1.5V/1.5V) along with 20 K pulsative endurance at RT and 105 s retention at 85 °C. We have also described the diffusivity of Silver (Ag) active metal electrode into deposited insulating layers and physics behind BRS and RRS dynamics in fabricated device.

Performance Evaluation of Low-Temperature KF-NaF-AlF3 Electrolytes for Aluminum Electrolysis Using Vertical Inert Cu–Ni–Fe Alloy Anodes

In this study, the performance of low-temperature electrolytes in a 40 A laboratory oxygen-evolving aluminum electrolysis cell with vertical inert electrodes for two compositions of NaF-KF-AlF3 based electrolyte is investigated. Two compositions of Cu–Ni–Fe alloy, single-phase homogenized, 20Cu-42Ni-38Fe wt% and 5Cu-48Ni-47Fe wt%, are evaluated as anodes. Titanium diboride (TiB2) is used as a wetted cathode. The characteristics of a protective oxide layer, pre-formed on the anode through high-temperature air oxidation, are examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is found that a multilayered oxide morphology, revealing Fe2O3 and NiFe2O4 as major constituents, is dense and adherent to the base alloy. The effects of electrolyte compositions, anode alloys, and electrolysis conditions on cell voltage evolution, current efficiency, contamination levels in the electrolyte and produced aluminum, and anode wear rate are systematically studied. A protective oxide layer, formed through oxidation treatment on the 20Cu-42Ni-38Fe wt% alloy, not only remains compact post-electrolysis but also performs significantly better in a K-rich electrolyte in terms of wear rate and the purity of the aluminum obtained. Influences of electrolyte composition on anode degradation behavior are discussed.

Simultaneous phosphorus precipitation and sludge thickening by electrolysis with an anode covered by bivalve shells

A wastewater treatment plant with a large inflow of phosphorus (P) is a potential P source that can act as an alternative to phosphate rocks and a renewable source of P. During electrolysis with inert electrodes, hydroxide ions generated from the cathode cause calcium phosphate (CaP) precipitation, and oxygen and hydrogen generated from the electrodes cause thickening of the sludge by electroflotation in sludge treatment streams. However, these two effects have not been achieved simultaneously because the precipitation of CaP requires much more time than that required for thickening by electroflotation. In this study, an electrolysis system that used an anode covered with bivalve shells was used. Batch experiments were conducted and the results demonstrated that covering the anode with shells resulted in their dissolution and that the calcium ions provided by this process considerably enhanced P removal in the form of CaP, thereby shortening the time required for CaP precipitation. In continuous experiments with excess sludge, electrolysis with shells accomplished sludge thickening by electroflotation (the thickened sludge had 5.5 times the total solids in the original excess sludge) and low relative phosphate-P concentrations (0.0545–0.0812) in the effluent compared to the influent. This effect is attributed to CaP precipitation. Additional mixing of the CaP precipitates in the effluent enhanced their settleability. The results demonstrate that electrolysis using an anode covered with bivalve shells simultaneously achieved CaP precipitation and sludge thickening.