Cathode Surface Research Articles

Omni-functional simultaneous interfacial treatment for enhancing stability and outgassing suppression of lithium-ion batteries

Ni-rich layered oxides in lithium-ion batteries have problems with gas generation and electrochemical performance reduction due to residual lithium’s reaction on the surface with the electrolyte. To address this issue, in this study, the Acid solvent evaporation (ASE) method has been proposed as a potential method to remove residual lithium while promoting the formation of a new LiNO3-derived coating layer on the cathode surface. The reduction of residual lithium using the ASE method and the construction of a LiNO3-derived coating layer suppresses gas evolution caused by the side effects of the electrolyte, improves electrochemical performance, and improves thermal stability by facilitating the smooth movement of lithium ions. Furthermore, the structural stability and resistance change due to the LiNO3-derived coating layer effects is guaranteed through cycling and DCIR of the pouch cell. As a result, compared to Pristine, the capacity retention of coin cells increased by 8% after 100 cycles, and pouch cells increased by 25% after 160 cycles. In addition, after cycling the pouch cell, CO2 gas has significantly reduced by about 30% compared to Pristine using gas chromatography. The ASE method effectively forms a robust LiNO3-derived coating layer on the cathode active material, which helps minimize electrolyte reactivity, suppress CO2 emissions, enhance surface structure stability, improve thermal stability, and improve overall battery performance.

Electrochemical conversion of contaminant p-nitrophenol to p-aminophenol and high-value p-quinones: Mechanism, kinetics and modeling

Understanding the chemistry of contaminant p-nitrophenol (p-NP) in electrochemical systems is of importance to remove it from wastewater and to produce high-value products such as quinones. In this study, redox experiments in a system initially containing an aqueous solution of sodium chloride and p-NP at pH 5 and 25 °C were performed in an electrochemical reactor with low-cost steel electrodes. The reactor was operated at 0.1 and 0.2 A, and at initial p-NP concentrations of 4.04×10−5, 6.97×10−5 and 10.3×10−5 M. Air and argon were bubbled at the bottom of the cathode to have solutions saturated with O2 (7.7 mg L−1) and free of dissolved O2. At these conditions p-NP was completely converted to less toxic and more valuable p-hydroquinone and p-aminophenol in an hour. The reaction rates were individually controlled by the steps of electron transfer and adsorption of p-NP at the cathode surface. In the presence of dissolved O2, p-hydroquinone and p-aminophenol were intermediate species oxidized to p-benzoquinone, and p-quinoneimine in the greatest amount, respectively. The rate constants for the reactions were determined on the basis of kinetic results obtained by liquid chromatography and spectrophotometry. The suggested mechanism, and the innovative kinetic model involving Langmuir-Hinshelwood rate expressions for the surface reactions, were consistent with results from mass spectrometry and total organic carbon. For the first time for this kind of kinetic model, it was also able to reproduce a large set of kinetic data of electroreduction of p-NP with iron electrodes obtained by independent researchers at several different conditions.

Modeling of the influence of field electron emission from a cathode with a thin insulating film on its sputtering in a gas discharge in a mixture of argon and mercury vapor

A model of the low-current gas discharge in a mixture of argon and mercury vapor in the presence of a thin insulating film on the cathode surface is proposed. The model takes into account that in such a mixture a substantial contribution to the ionization of the working gas can come from the ionization of mercury atoms during their collisions with metastable excited argon atoms. In the discharge, positive charges accumulate on the film surface, creating an electric field in the film sufficient to cause field emission of electrons from the cathode metal substrate into the insulator. Such electrons are accelerated in the film by the field and can escape from it into the discharge volume. As a result, the effective yield of ion-electron emission from the cathode increases. The temperature dependences of discharge characteristics are calculated and it is shown that, due to a rapid decrease in the concentration of mercury vapor in the mixture with decreasing temperature, the electric field strength in the discharge gap and the discharge voltage increase. The presence of a thin insulating film on the cathode can result in an improvement in its emission characteristics and a significant reduction in the discharge voltage. This causes a decrease in the energies of the ions and atoms bombarding the cathode surface, and, consequently, in the intensity of cathode sputtering in the discharge.

Oxygen Transport through Amorphous Cathode Coatings in Solid-State Batteries.

All solid-state batteries (SSBs) are considered the most promising path to enabling higher energy-density portable energy, while concurrently improving safety as compared to current liquid electrolyte solutions. However, the desire for high energy necessitates the choice of high-voltage cathodes, such as nickel-rich layered oxides, where degradation phenomena related to oxygen loss and structural densification at the cathode surface are known to significantly compromise the cycle and thermal stability. In this work, we show, for the first time, that even in an SSB, and when protected by an intact amorphous coating, the LiNi0.5Mn0.3Co0.2O2 (NMC532) surface transforms from a layered structure into a rocksalt-like structure after electrochemical cycling. The transformation of the surface structure of the Li3B11O18 (LBO)-coated NMC532 cathode in a thiophosphate-based solid-state cell is characterized by high-resolution complementary electron microscopy techniques and electron energy loss spectroscopy. Ab initio molecular dynamics corroborate facile transport of O2- in the LBO coating and in other typical coating materials. This work identifies that oxygen loss remains a formidable challenge and barrier to long-cycle life high-energy storage, even in SSBs with durable, amorphous cathode coatings, and directs attention to considering oxygen permeability as an important new design criteria for coating materials.

Regulating interfacial chemistry and kinetic behaviors of F/Mo co-doping Ni-rich layered oxide cathode for long-cycling lithium-ion batteries over −20 °C–60 °C

Ni-rich layered oxide cathodes have shown promise for high-energy lithium-ion batteries (LIBs) but are usually limited to mild environments because of their rapid performance degradation under extreme temperature conditions (below 0 °C and above 50 °C). Here, we report the design of F/Mo co-doped LiNi0.8Co0.1Mn0.1O2 (FMNCM) cathode for high-performance LIBs from −20 to 60 °C. F– doping with high electronegativity into the cathode surface is found to enhance the stability of surface lattice structure and protect the interface from side reactions with the electrolyte by generating a LiF-rich surface layer. Concurrently, the Mo6+ doping suppresses phase transition, which blocks Li+/Ni2+ mixing, and stabilizes lithium-ion diffusion pathway. Remarkably, the FMNCM cathode demonstrates excellent cycling stability at a high cutoff voltage of 4.4 V, even at 60 °C, maintaining 90.6% capacity retention at 3 C after 150 cycles. Additionally, at temperatures as low as −20 °C, it retains 77.1% of its room temperature capacity, achieving an impressive 97.5% capacity retention after 500 cycles. Such stable operation under wide temperatures has been further validated in practical Ah-level pouch-cells. This study sheds light on both fundamental mechanisms and practical implications for the design of advanced cathode materials for wide-temperature LIBs, presenting a promising path towards high-energy and long-cycling LIBs with temperature adaptability.

Ion migration mechanism of electrochemical water softening in dual-chamber reactors and their performance for real circulating cooling water

Electrochemical water softening studies often use ion exchange membrane (IEM) reactors. However, their practical application is limited because of inevitable cathodic scaling. To overcome this challenge, one necessary approach is to understand the ion migration mechanism in the typical IEM reactor. In this study, we used operando visualization to reveal that the divider such as IEM or nylon nets was essential to confine the neutralization reaction between H+ and OH−. Ca2+ and Mg2+ may transfer from the anode chamber through the divider into the cathode chamber via electromigration. Using mesh electrodes instead of plate electrodes, the total hardness removal in the cathode chamber and anode chamber was 94.2% and 92.5%, respectively. The high removal rate was attributed to H2 microbubbles produced by cathodic water electrolysis, which drove OH− ions diffusion into solution and sequentially strengthened the nucleation of scale crystals in solution rather than on the cathode surface. On the basis of the above ion migration mechanism, the revolutionized reactor with mesh electrode module and nylon-net divider exhibited good performance in softening real circulating cooling water, and the total hardness removal exceeded 93.1% during 30 h running. These results open new horizons for improving the practicability of electrochemical water softening.

Surface Lattice Modulation Enables Stable Cycling of High‐Loading All‐solid‐state Batteries at High Voltages

AbstractHalide solid electrolytes, known for their high ionic conductivity at room temperature and good oxidative stability, face notable challenges in all–solid–state Li–ion batteries (ASSBs), especially with unstable cathode/solid electrolyte (SE) interface and increasing interfacial resistance during cycling. In this work, we have developed an Al3+–doped, cation–disordered epitaxial nanolayer on the LiCoO2 surface by reacting it with an artificially constructed AlPO4 nanoshell; this lithium–deficient layer featuring a rock–salt–like phase effectively suppresses oxidative decomposition of Li3InCl6 electrolyte and stabilizes the cathode/SE interface at 4.5 V. The ASSBs with the halide electrolyte Li3InCl6 and a high–loading LiCoO2 cathode demonstrated high discharge capacity and long cycling life from 3 to 4.5 V. Our findings emphasize the importance of specialized cathode surface modification in preventing SE degradation and achieving stable cycling of halide–based ASSBs at high voltages.

Novel Additives in Copper Electrorefining-Small Laboratory Scale.

This research aimed to evaluate the effectiveness of new organic substances, including a novel ionic liquid based on polyhexamethylenebiguanidine, polyhexamethyleneguanidine, and safranin in the copper electrorefining process. Experiments were conducted on a small laboratory scale using industrial copper anodes. Single doses of new additives did not improve process indicators (current efficiency, average cell voltage, specific energy consumption) or the quality of copper cathode deposits. However, a combination of a new ionic liquid based on polyhexamethylenebiguanidine and thiourea resulted in a satisfactory current efficiency of 97%, an average cell voltage of 0.110 V, a low specific energy consumption index of approximately 100 kWh/tCu, and smooth cathode surfaces. These results were superior to those obtained with industrial additives (bone glue and thiourea). The findings enhance our understanding of how these substances influence the electrorefining process and suggest the potential for more efficient and sustainable methods. Further research is recommended to validate these findings and explore their industrial applications.

Surface Lattice Modulation Enables Stable Cycling of High-Loading All-solid-state Batteries at High Voltages.

Halide solid electrolytes, known for their high ionic conductivity at room temperature and good oxidative stability, face notable challenges in all-solid-state Li-ion batteries (ASSBs), especially with unstable cathode/solid electrolyte (SE) interface and increasing interfacial resistance during cycling. In this work, we have developed an Al3+-doped, cation-disordered epitaxial nanolayer on the LiCoO2 surface by reacting it with an artificially constructed AlPO4 nanoshell; this lithium-deficient layer featuring a rock-salt-like phase effectively suppresses oxidative decomposition of Li3InCl6 electrolyte and stabilizes the cathode/SE interface at 4.5 V. The ASSBs with the halide electrolyte Li3InCl6 and a high-loading LiCoO2 cathode demonstrated high discharge capacity and long cycling life from 3 to 4.5 V. Our findings emphasize the importance of specialized cathode surface modification in preventing SE degradation and achieving stable cycling of halide-based ASSBs at high voltages.

Influence of Ti2SnC content on arc erosion resistance in Ag–Ti2SnC composites

Abstract In this work, an Ag–Ti2SnC composite was fabricated by the hot-pressing sintering method, and the erosion behavior of Ag–Ti2SnC with volume percentages of 10–40% was studied at a load voltage of 10 kV. The arc life and breakdown current were observed at about 31–36 ms and 39 A, respectively. The cathode spot traveled the fastest on the surface of the Ag–40 vol% Ti2SnC composite. Due to emission center model, the temperature of the minor protrusions on the cathode surface increased, resulting in Ag ions, Ti ions, and Sn ions being generated. Combining with the ionized oxygen, Ag2O, AgO, TiO2, and SnO2 were formed on the eroded Ag–Ti2SnC surface after arc erosion. The research results will broaden the application range of Ag–Ti2SnC electrical contact material and enrich the arc erosion mechanism.

Investigating Cathode Electrolyte Interphase Formation in NMC 811 Primary Particles through Advanced 4D-STEM ACOM Analysis

Investigating Cathode Electrolyte Interphase Formation in NMC 811 Primary Particles through Advanced 4D-STEM ACOM Analysis

Hierarchically Interconnected 3D Catalyst Structure of Porous Multi-Metal Oxide Nanofibers for High-Performance Li-O2 Batteries.

Non-aqueous lithium-oxygen batteries (LOBs) have emerged as a promising candidate due to their high theoretical energy density and eco-friendly cathode reaction materials. However, LOBs still suffer from high overpotential and poor cycling stability resulting from difficulties in the decomposition of discharge reaction Li2O2 products. Here, a 3D open network catalyst structure is proposed based on highly-thin and porous multi-metal oxide nanofibers (MMONFs) developed by a facile electrospinning approach coupled with a heat treatment process. The developed hierarchically interconnected 3D porous MMONFs catalyst structure with high specific surface area and porosity shows the enhanced electrochemical reaction kinetics associated with Li2O2 formation and decomposition on the cathode surface during the charge and discharge processes. The uniquely assembled cathode materials with MMONFs exhibit excellent electrochemical performance with energy efficiency of 82% at a current density of 50mAg-1 and a long-term cycling stability over 100 cycles at 200mAg-1 with a cut-off capacity of 500 mAhg-1. Moreover, the optimized cathode materials exhibit a remarkable energy density of 1013Whkg-1 at the 100th discharge and charge cycle, which is nearly four times higher than that of C/NMC721, which has the highest energy density among the cathode materials currently used in electric vehicles.

Unlocking superior safety, rate capability, and low-temperature performances in LiFePO4 power batteries

The safety concerns associated with lithium-ion batteries (LIBs) have sparked renewed interest in lithium iron phosphate (LiFePO4) batteries. It is noteworthy that commercially used ester-based electrolytes, although widely adopted, are flammable and fail to fully exploit the high safety potential of LiFePO4. Additionally, the slow Li+ ion diffusion and low electronic conductivity of LiFePO4 batteries limit their utility in high-power applications. Despite the crucial role played by liquid electrolytes in LIBs, achieving simultaneous improvements in safety, rate capability, and low-temperature performance remains a formidable challenge. In this study, we addressed these challenges by innovatively applying a single solvent ethyl vinyl sulfone (EVS) electrolyte to graphite/LiFePO4 batteries. While renowned for its broad electrochemical window, low freezing point and superior safety performance, the EVS electrolyte exhibited compatibility issues with the graphite anode. To overcome this hurdle effectively, we utilized vinylene carbonate as an additive with lower reductive reactivity than EVS to modify the interphase formed by EVS successfully. Simultaneously, the EVS-based electrolyte was found to create a sulfone-rich interphase on the LiFePO4 cathode surface, significantly enhancing Li+ ion diffusion both across the interphase and within the material. These modifications culminated in a conspicuous improvement in the performance of graphite/LiFePO4 batteries. Our study illuminates the potential of EVS-based electrolytes in boosting the rate capability, low-temperature performance, and safety of LiFePO4 power lithium-ion batteries. It yields valuable insights for the design of safer, high-output, and durable LiFePO4 power batteries, marking an important stride in battery technology research.

Rate-limiting mechanism of all-solid-state battery unravelled by low-temperature test-analysis flow

All-solid-state batteries (ASSBs) with potentially improved energy density and safety have been recognized as the next-generation energy storage technology. However, their performances at subzero temperatures are rarely investigated, with rate-limiting process/mechanisms unidentified. Herein, the rate-limiting process/mechanisms for -40℃ ASSBs are accurately identified/analyzed by developing a standard test-analysis flow model. We reveal that the rate-limiting processes of LiCoO2 (LCO)+sulfide solid electrolyte (SE) composite cathode are the sluggish ion transport across unfavorable interfacial reaction layer and charge transfer at damaged LCO cathode surface. After inserting Li2ZrO3 (LZO) coating layer to suppress interfacial reactions, the rate-limiting process of LCO@LZO+sulfide SE composite cathode turns into the arduous ion transport across the interphase composed of the self-decomposition products of sulfide SE. Interestingly, by replacing sulfide SE with halide SE, LCO+halide SE composite cathode delivers fast charge transfer and the ion conduction through the thick SE separator becomes the rate-limiting process, thus enabling a superior capacity retention rate (41.4 %) at -40℃. Furthermore, the capacity retention of ASSB coupling LCO+halide SE composite cathode with Si anode can be boosted from 28.9 % to 38.6 % at -40℃ by employing superionic conductor with low activation energy. These successful identifications/modulations on rate-limiting process/mechanism and improvements on low-temperature performance demonstrate the significant role of this test-analysis flow in propelling the development of low-temperature ASSBs.

Electrolyte Regulation in Stabilizing the Interface of a Cobalt-Free Layered Cathode for 4.8 V High-Voltage Lithium-Ion Batteries.

The cobalt-free layered oxide cathode of LiNi0.65Mn0.35O2 is promising for high-energy-density lithium-ion batteries (LIBs). However, under high-voltage conditions, severe side reactions between the Co-free cathode and electrolyte, as well as grain boundary cracks and pulverization of particles, hinder its practical applications. Herein, an electrolyte regulation strategy is proposed by adding fluoroethylene carbonate (FEC) and LiPO2F2 as electrolyte additives in carbonate-based electrolytes to address the above issues. As a result, a homogeneous and dense organic-inorganic hybrid cathode electrolyte interface (CEI) film is formed on the cathode surface. The CEI film consists of C-F, LiF, Li2CO3, and LixPOyFz species, which is proven to be highly conductive and effective in suppressing structure damage and alleviating the interfacial reactions between the cathode and electrolyte. With such a CEI film, the interfacial stability of the Co-free cathode and the high-voltage cycling performance of Li||LiNi0.65Mn0.35O2 are greatly improved. A reversible capacity of 155.1 mAh g-1 and a capacity retention of 81.3% over 150 cycles are attained at a 4.8 V charge cutoff voltage with the tamed electrolyte, whereas the cell without the additives only retains 76.1% capacity retention. Therefore, our work demonstrates the synergistic effect of FEC and LiPO2F2 in stabilizing the interface of Co-free cathode materials and provides an alternative strategy for the electrolyte design of high-voltage LIBs.

Mass/heat transfer analogy method in the research of convective fluid flow through channels with a specific geometry

The present work contains the results of the comparative analysis of the literature data and the own investigations on mass and heat transfer coefficients occurring under conditions of the convective fluid flow through channels characterised by a specific geometry. The authors focused on the available experimental investigations on mass transfer. The considered experiments were carried out using the electrochemical method named limiting current technique. Two channel geometries were discussed: the annular channel of the conventional size and the long minichannel with a square cross-section area. Taking into consideration dimensionless numbers: Schmidt and Nusselt – analogical for mass and heat transfer – the formulas describing the phenomena under consideration were included. In the case of the annular channel the laminar and turbulent range of Reynolds numbers was studied. For the square minichannel – the laminar flow is considered. The analogy between mass and heat transfer introduced by Chilton and Colburn was applied in the analysis. An equivalent boundary condition is included in considerations concerning the mass and heat transfer. It is the Dirichlet boundary condition characterised by constant temperature of the wall which corresponds to the situation of constant ion concentration at the cathode surface in the limiting current technique. The main purpose of the present work was to verify the method for the determination of heat transfer coefficients using the analogy between mass and heat transfer processes in the case of convective fluid flow through the annular and square channels. The problem discussed in the present work is important and actual due to the possibility of the elimination of temperature measurements in the investigations of heat transfer processes occurring in channels characterised by a specific geometry. It should be noted that sometimes temperature measurement may be difficult or even impossible. This situation also causes high uncertainty of the obtained results. Due to this problem, the presented analysis was performed also with the use of thermal results based on the analytical solution. The verification of the use of mass/heat transfer analogy method in specific cases gives the extended knowledge of correct application of the limiting current technique in heat transfer research. The main objective of the work was achieved by conducting a comparative analysis of the adequate mass and heat transfer results. The existing literature data do not provide an answer to the question about the correctness of using the limiting current technique in the case of discussed annular channels or long square minichannels. The received results make us be critical of applying the mass/heat transfer analogy method in some heat transfer cases.

Effects of chloride ion concentration on porous surfaces and boiling heat transfer performance of porous surfaces

Porous surfaces are a common modified surface used to enhance boiling heat transfer. In this paper, a method for preparing gradient porous surfaces is presented, that is, magnetic stirring is added to the electrolyte and the cathode surface to be deposited is placed vertically downward. Within the Cl ion concentration range of 30–140 mg/L, increasing the Cl ion concentration results in lager pore sizes. When the Cl concentration was greater than 120 mg/L, the average pore size of the surface gradually increased from the center to the edge, and the number of pores gradually decreased from the center to the edge. All surfaces showed superhydrophilicity. The critical heat flux of Sample#3 is 158.72 W/cm2, which is 67% higher than the smooth surface. The wall superheat of Sample#3 was only 15 °C in the critical state. This porous surface has plenty of nucleation sites. These nucleation sites are gradually activated when the heat flux increases. At low heat fluxes, heat transfer on these porous surfaces presents a disadvantage because the nucleation sites are not fully activated. At high heat fluxes, these porous surfaces show a decrease in wall temperature. Consequently, the porous surface prepared in this paper has good boiling heat transfer at high heat flux.

Efficient and Selective Electrochemical Nitrate Reduction to N2 Using a Flow-Through Zero-Gap Electrochemical Reactor with a Reconstructed Cu(OH)2 Cathode: Insights into the Importance of Inter-Electrode Distance.

Electrochemically converting nitrate, a widely distributed nitrogen contaminant, into harmless N2 is a feasible and environmentally friendly route to close the anthropogenic nitrogen-based cycle. However, it is currently hindered by sluggish kinetics and low N2 selectivity, as well as scarce attention to reactor configuration. Here, we report a flow-through zero-gap electrochemical reactor that shows a high performance of nitrate reduction with 100% conversion and 80.36% selectivity of desired N2 in the chlorine-free system at 100 mg-N·L-1 NO3- while maintaining a rapid reduction kinetics of 0.07676 min-1. More importantly, the mass transport and current utilization efficiency are significantly improved by shortening the inter-electrode distance, especially in the zero-gap electrocatalytic system where the current efficiency reached 50.15% at 5 mA·cm-2. Detailed characterizations demonstrated that during the electroreduction process, partial Cu(OH)2 on the cathode surface was reconstructed into stable Cu/Cu2O as the active phase for efficient nitrate reduction. In situ characterizations revealed that the highly selective *NO to *N conversion and the N-N coupling step played crucial roles during the selective reduction of NO3- to N2 in the zero-gap electrochemical system. In addition, theoretical calculations demonstrated that improving the key intermediate *N coverage could effectively facilitate the N-N coupling step, thereby promoting N2 selectivity. Moreover, the environmental and economic benefits and long-term stability shown by the treatment of real nitrate-containing wastewater make our proposed electrocatalytic system more attractive for practical applications.

Polysulfide-mediated solvation shell reorganization for fast Li+ transfer probed by in-situ sum frequency generation spectroscopy

Understanding of interfacial Li+ solvation shell structures and dynamic evolution at the electrode/electrolyte interface is requisite for developing high-energy-density Li batteries. Herein, the reorganization of Li+ solvation shell at the sulfur/electrolyte interface along with the presence of a trace amount of lithium polysulfides is verified by in-situ sum frequency generation (SFG) spectroscopy together with density functional theory (DFT) calculations. Both the spectroelectrochemical and DFT calculation results reveal a strongly competitive anion adsorption of the polysulfide anion additive against the pristine electrolyte anion on the sulfur cathode surface, reorganizing the interfacial local solvation shell structure facilitating rapid Li ion transfer and conduction. Meanwhile, the evolution of the SFG signals along with the discharging/charging cycle exhibits improved reversibility, indicating the transformation of the inner Helmholtz plane layer into a stable molecular-layer polysulfide interphase rather than a dynamic diffusion layer. Consequently, applications in practical Li-S batteries reveal the capacity and cycling stability of the corresponding cells are significantly enhanced. Our work provides a methodology using in-situ SFG for probing solvation reorganization of charge carriers at electrochemical interfaces.

High-flux electrochemical phosphorus recovery in an undivided electrolytic cell coupled with microfiltration with low energy consumption

Electrochemical systems are promising for phosphorus (P) removal and recovery from wastewater. However, its industrial application still faces some challenges, including relatively low P recovery efficacy, high energy consumption, and complex configuration of the reactors. This work, developed an undivided electrolytic cell with H+ or OH− extraction from its corresponding electrode surface for P recovery. The experimental results and models validated the superiority of continuously and precisely extracting H+ from the tubular Ti porous anode surface for H+–OH− separation over OH− extraction from the cathode surface. In the electrolytic cell, alkaline effluent with H+ extraction, the P could be precipitated with Ca2+ in the form of insoluble calcium phosphate (Ca-phosphate), which could then be separated from the wastewater by microfiltration. Under the conditions of a current density of 4 mA cm−2, an initial P concentration of 0.6 mM, a influent flow rate of 500 mL min−1, and H+ extraction rate of 50 mL min−1, the P recovery efficiency reached 81 % with the alkaline effluent pH of 10.5. The calculated P recovery rate and treatment capacity were 18.3 g P (m2 h)-1 and 1194 L (m2 h)-1, respectively, at energy consumption of 8.75 kWh (kg P)-1, which were superior over the cutting-edge divided electrolytic systems and the conventional undivided electrolytic systems. The recovered precipitates are composed principally of hydroxyapatite in the minor presence of amorphous calcium phosphate, showing a Ca/P molar ratio of 1.8. Generally, the established undivided electrolytic cell coupled with microfiltration exhibited significant prospects for recovering P from wastewater without acid-base reagents.