Hicham Ben Youcef

• Professor
• Professor (Associate) at Mohammed VI Polytechnic University

Tremendous efforts are deployed to tackle the challenges facing the pioneering technology of lithium-ion batteries (LIBs). High performance, high safety, long lifetime, and cost-efficiency are the main requirements to address. Metal alloys have demonstrated high capacities and good electronic conductivity. However, they undergo several structural c...

Due to their high volumetric energy density, lithium-ion batteries (LIBs) play a key role in today’s society. They are applied in the portable electronics industry and plug-in hybrid electric vehicles. There has been a greater focus on research on electrode materials for LIBs considering that they are the main factor determining the overall capacit...

The goal of this study is to provide new insights into the corrosion mechanism of core‐shell carbides containing steels. The corrosion behavior of two heat‐treated Cr–W–V–Mo‐rich stainless steels is evaluated using electrochemical techniques. The studied steels have different carbides microstructure, the first has core–shell carbides (Cr 7 C 3 –Cr...

Since the emergence of research on cathode materials for sodium-ion batteries, numerous chemical compositions were investigated as potential promising candidates. Layered transition metal oxides, polyanionic compounds, and Prussian blue analogues are the main reported categories. Their practical use in large-scale applications depends on maintainin...

High-entropy materials for thermoelectric applications: towards performance and reliability The new concept of high-entropy materials has unlocked the door to a wide range of applications such as thermoelectrics. Through the mixing of different elements, which leads to lattice distortion, the heat-carrying phonons are scattered, leading to reduced...

High-entropy materials (HEMs), including alloys, ceramics and other entropy-stabilized compounds, have attracted considerable attention in different application fields. This is due to their intrinsically unique concept and properties, such as innovative chemical composition, structural characteristics, and correspondingly improved functional proper...

Nafion has been dominating the proton exchange membrane (PEM) market because of its adequacy for the proton exchange operation. However, because of its high cost, low performance at low relative humidity, and finally environmental unfriendliness, researchers have been developing and working on Nafion alternatives. In this review, we assess how biop...

Contamination by toxic heavy metals is a serious issue due to their toxicity, persistence, and bioaccumulative nature. They are released into the environment and reach the human body as individuals or metal mixtures, causing serious biological and physiological complications. The detoxification actions should begin with modifications within the eco...

To meet the needs of a rapidly expanding global population, farmers will need more fertilizers than ever before to maintain a steady supply of affordable, nutritious food. The formulation of controlled release fertilizers (CRF) to synchronize nutrient release according to the demand of plants has emerged as a viable solution to the current problems...

Hydroxyapatite (HA) and chitosan (CS) biopolymer are the major materials investigated for biomedical purposes. Both of these components play an important role in the orthopedic field as bone substitutes or drug release systems. Used separately, the hydroxyapatite is quite fragile, while CS mechanical strength is very weak. Therefore, a combination...

This work reports the synthesis of a NaSICON-type structure material, a cost-efficient electrode for lithium-ion batteries, by the substitution of vanadium with cost-effective and eco-friendly iron. Li3.27FeII0.19FeIII0.81V(PO4)3 was synthesized using sol-gel followed by a calcination at 450 °C under argon. XRD has confirmed the successful preparat...

A novel strategy was developed to prepare a self-blowing poly(β-hydroxythioether) foam at room temperature by S-alkylation of 5-membered bis-cyclic carbonate using multifunctional thiol monomers. Two different thiol compounds, trimethylolpropane tris(3-mercaptopropionate) and pentaerythritol tetrakis(3-mercaptopropanoic acid) were used for the deca...

This study aims at understanding the effect of different heat treatments on the evolution of the microstructure of several Cr–W–V–Mo steels having different compositions and how this latter affects their abrasion resistance. The investigation also gives insights on the formation and effect of core-shell carbides on the abrasion resistance. The comm...

This work aims to develop an injectable and antibacterial composite cement for bone substitution and prevention/treatment of bone infections. This cement is composed of calcium phosphate, calcium carbonate, bioactive glass, sodium alginate, and ciprofloxacin. The effect of ciprofloxacin on the microstructure, chemical composition, setting propertie...

Phosphorylated cellulose nanofiber (CNF-P) is presented as novel and promising organic filler for the preparation of composite solid polymer electrolytes (SPE). The degree of phosphorylation was evaluated, and the CNF-P was characterized. The results show that the phosphorus incorporation promotes the flame-retardancy property of cellulose nanofibe...

Na2FePO4F fluorophosphate has long been regarded as potential cathode material for sodium-ion batteries (SIBs) due to its undeniable economic and environmental advantages. Herein, the preparation of Na2FePO4F powder using an easier and cost-effective technique is reported. The prepared compound, using phosphoric acid as P-source, crystallizes in an...

This work presents a mathematical tool to estimate the cost of fabricating pumps by traditional casting. The drivers that most affect the cost of the process are identified in each step of the procedure, i.e., material, labour, energy, tools and general expenses associated with any industrial activity. The mathematical expressions used for the calc...

A chitosan gel additive modulates the initial vaterite dissolution–recrystallisation in injectable aragonite-based composite cement and promotes its in vitro bioactivity.

The study evaluates the microstructure, abrasion resistance, and corrosion behavior of newly designed cost-effective (Cr-Mo-W-V) steels. Six steels were designed with the help of computational thermodynamics to achieve a ferritic or duplex matrix with embedded hard carbides. The precursors of alloying elements were two commercial steels, namely HCx...

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites loaded with ciprofloxacin antibiotic (HA–CS–CIP) were formulated using the in situ and the solid-liquid method coupled with the freeze-drying process. The interaction of the HA-CS composite powder and ciprofloxacin antibiotic (CIP) was investigated by batch adsorption essays. The kinetic...

In this study, microcrystalline cellulose (MCC) was phosphorylated using phosphoric acid in the presence of urea and used as an adsorbent for methylene blue (MB) dye removal from an aqueous solution. The obtained products were characterized by different techniques. Batch adsorption experiments were conducted under varying conditions of incubation t...

In the perspective of preparing coating material of water-soluble fertilizer with controlled and slow-release property, polymethyl methacrylate (PMMA) was grafted from carboxymethyl cellulose (CMC) through in-situ polymerization using potassium persulfate (KPS) as initiator. The prepared copolymers (PMMA-g-CMC) were fully characterized using Transf...

Safe energy storage technique is prerequisite for sustainable energy development in the future. Designing Solid-State Electrolytes exhibiting high ionic conductivity, good electrochemical performances, high mechanical/thermal stability, compatible electrolyte/electrode interface is the main concern for developing the next-generation rechargeable ba...

This study reports for the first time the effect of particle size of bioactive glass 46S6 on the physico-chemical and mechanical properties of carbonated apatite cement (CPC) composed of brushite (CaHPO4. H2O) and vaterite (CaCO3). Three particle size ranges were investigated: coarse (BGc: 100–200μm), medium (BGm: 40–100μm), and fine (BGf<40 μm). F...

Nitrogen, phosphorus, and potassium are the major nutrients solicited in the fertilization process, and their supply is highly useful to improve agricultural productivity. The conventional fertilizers suffer from low efficacy due to the fast release of nutrients. For that, the coating of granular fertilizer is considered as the best way to enhance...

Smart materials based on the self-healing concept are used in different advanced applications such as buildings, batteries and coatings. The development of these materials follows two scenarios: the development of materials with intrinsic self-healing properties, or the preparation of extrinsic self-healing materials containing adds such as microca...

The search for alternatives to the existing energy model is focusing on the use of renewable energies. Due to the fluctuations in energy and the mismatch between the energy supply and its demand, the search for a technology that efficiently stores the energy that is generated in order to use it when necessary is of vital importance. Electrochemical...

Iron (III) transition metal MFeOPO4@C (M: Co, Ni) oxyphosphates were synthesized using a solid-state reaction. The electrochemical properties of MFeOPO4@C were evaluated versus Li⁺/Li using two different binders (PVDF and CMC) in the voltage range 0.01-3.0 V. These phosphates show similar electrochemical profiles for both binders. They deliver a hi...

A correlation between the crystal structure, the ionic conductivity and the electrochemical performance in Lithium-ion batteries was established for a series of NASICON-type phosphates Li0.5M0.5Ti1.5Fe0.5(PO4)3 (M = Mn, Co, Mg). These electrode materials, where the M1 site contains both lithium and the divalent cation M, were prepared using a simpl...

Enhancing the sorption properties of cellulose is a prerequisite for its efficient use in water purification as an alternative to costly activated carbon. Here, solvent-free phosphorylation of cellulose using environmentally benign and non-toxic chemicals was pursued resulting in a negatively charged material that was used to remove methylene blue...

Carboxymethyl chitin (CMChit) has the potential to be used as a solid polymer electrolyte (SPE) based on its ionic conductivity value of the order of 10⁻⁶ S·cm⁻¹ in self-standing membranes. In controlled humidity of 65RH%, carboxymethyl chitin based membrane blended with 1-Butyl-3-methylimidazolium acetate (BMIM[Ac]) ionic liquid (IL) ( 40 wt%) sho...

The consequence of coupling wear (erosion/abrasion) and corrosion is not just simply the sum of wear in the absence of corrosive medium and corrosion in absence of wear. The so-called synergistic effect implies that corrosion is accelerated due to the removal of the passivating layer because of wear. On the other hand, corrosion can accelerate abra...

This work reports on the preparation of oil-filled microcapsules for self-healing purposes. Biopolymeric microcapsules loaded with vegetable oils as green corrosion inhibitors were formulated using ethyl cellulose and phosphorylated ethyl cellulose as encapsulating materials. Chemical structure, thermal stability and surface morphology of microcaps...

Calcium phosphate cements (CPC) have been widely investigated as bone substitutes, owing to their attractive features in terms of physicochemical and biocompatibility properties. However, the clinical applicability of this group of biomaterials is still critically limited by its poor strength and rheological properties in terms of injectability and...

A composite based on hydroxyapatite (HA) and chitosan (CS) combined with ciprofloxacin (CIP) was formulated by the solid–liquid mixing method. The optimization of the solid to the liquid ratio and the use of chitosan in a small amount (≤5 wt%) promoted the preparation of stable and rigid monoliths. A synergistic effect of CS and CIP contents on the...

The lack of the required mechanical strength and adequate biodegradation rate of calcium phosphate materials constitutes the most relevant drawback prohibiting their use for orthopaedic applications. One of the promising strategies to overcome this intrinsic limitation is the functionalization of these materials through the combination with specifi...

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on...

This study reports for the first time the preparation of almond oil-based microcapsules using phosphorylated ethyl cellulose as shell material. Microcapsules of ethyl cellulose (EC) and phosphorylated ethyl cellulose (P-EC) containing almond oil as anti-corrosion inhibitor, for end use in self-healing coatings, were prepared by a solvent evaporatio...

Phosphate materials became attractive electrode materials for sodium ion batteries due to their high capacity and safety properties. Cobalt iron (III) oxyphosphate CoFeOPO4@C was successfully prepared by conventional solid-state reaction at an annealing temperature of 1000 °C in air atmosphere. Our group previously reported the electrochemical prop...

Partial lithium substitution with nickel (0.25 of Ni²⁺ ion) in the previously reported Li1.5Fe0.5Ti1.5(PO4)3/C ([email protected]) was performed to improve its structural and electrochemical properties. The new LiNi0.25Fe0.5Ti1.5(PO4)3/C ([email protected]) material was then tested as electrode for lithium ion batteries. In the voltage window 1.85V...

The development of biodegradable based solid polymer electrolytes (SPE) has been intensively investigated in the last decades. These SPEs have shown promising results in electrochemical energy storage devices. Compatible Additives are added in order to overcome the low conductivity issue of pristine polysaccharide-based SPEs to improve their perfor...

Natrium super ionic conductor (NASICON) materials providing attractive properties such as the high ionic conductivity and good structural stability are considered as very promising materials for use as electrodes for lithium (LIBs) and sodium (NIBs) ion batteries. Herein, a new high-performance electrode material Li0.5Ni0.5Ti1.5Fe0.5(PO4)3/C was sy...

Green energy harvesting (solar and wind) and storage along with electrification of transport sector could bring about a major transformation in the CO2 emission levels that we are currently experiencing. Lithium ion batteries provide an efficient energy storage system to realize this goal. The key developments in Li-ion battery technology starting...

Solid polymer electrolytes (SPEs) with new functionalized ethyl cellulose bearing a lithium/sodium fluorosulfonylimide group (Ethyl cellulose-LiFSI/NaFSI) is proposed as quasi single ion (Li+/Na+) conducting polymer electrolyte for all-solid-state lithium and sodium batteries. The degree of ethyl cellulose functionalization by anion of lithium and...

A novel radiation grafted ETFE based proton conducting membrane was prepared by double irradiation grafting of two different monomers. The intrinsic oxidative stability of the ETFE-g-poly(styrene sulfonic acid-co-divinylbenzene) membrane was improved by reducing the gas crossover through incorporation of polymethacrylonitrile (PMAN) containing the...

Alfa fibers (Stipa Tenacissima) were effectively utilized in this study as a promising cellulose source for isolation of carboxy-functionalized cellulose nanofibrils (CNFs) using multiple treatments. Pure cellulose microfibers (CMFs) were firstly extracted by alkali and bleaching treatments. CNFs with an average nanofibrils diameter ranging from 1....

Design of novel phosphorus apatites, K2Pb6Zn2(PO4)6 and K2Pb4Ca4(PO4)6, zinc hydroxyapatite Ca8Zn2(PO4)6(OH)2, as well as hydroxyapatite Ca10(PO4)6(OH)2, and its corresponding calcined powder were conducted by means of two different synthesis protocols, i.e. solid state and wet chemical methods. The prepared materials adopt P63/m (No 176) as a spac...

The present work describes the production of novel highly hydrated cellulose microfibrils (CMFs) with unique morphology from coffee pulp waste using specific chemical treatments. The as-produced CMFs were successfully characterized and then used as an adsorbent for removal of methylene blue (MB) from concentrated aqueous solutions. Surprisingly, it...

The present invention refers to a method for preparing a solid polymer electrolyte based on modified cellulose, the method comprising the steps of: a) lithiation or sodiation of at least a hydroxyl group of each repeating unit of a “cellulose” to obtain Li (cellulose) or Na (cellulose); b) functionalization of the Li (cellulose) or Na (cellulose) o...

In recent years, much attention has been given to biopolymers with a focus on sustainable development and environmental preservation. Following this tendency, the attempt has been made to replace polymers derived from petroleum with superior biodegradable polymers; nevertheless, some of their physicochemical properties are required to be improved....

This work investigates the isolation of cellulose nanocrystals (CNC) from sugarcane bagasse (SCB) waste and the evaluation of their mechanical reinforcement capability for k-carrageenan biopolymer. The results from Atomic Force Microscopy and Transmission Electron Microscopy indicated the successful extraction of CNC from SCB following alkali, blea...

Cellulose nanocrystals (CNC) were extracted from Miscanthus (MST) fibers using a sulfuric acid hydrolysis process. The results showed that the obtained CNC exhibit a needle-like shape with an average aspect ratio of 37. The surface charge density was measured at 1.99 sulfate groups per 100 anhydroglucose units while the zeta potential value was fou...

The present invention refer to a method for preparing a solid polymer electrolyte based on modified cellulose, the method comprising the steps of: a) lithiation or sodiation of at least a hydroxyl group of each repeating unit of a “cellulose” to obtain Li (cellulose) or Na (cellulose); b) functionalisation of the Li (cellulose) or Na (cellulose) ob...

In this work, the effect of various polyol‐based plasticizers, including glycerol (GLY), diethylene glycol (DEG), and polyethylene glycol (PEG), on the properties of alginate (ALG)‐based films and cellulose nanocrystals (CNC)‐filled ALG‐based bionanocomposite films was investigated. The CNC used as nanoreinforcing fillers were extracted, at nanomet...

In the present work, cellulose nanocrystals (CNC) were produced from vine shoots waste using chemical treatments followed by acid hydrolysis process. FTIR analysis confirmed that the non-cellulosic components were progressively removed during the chemical treatments, and the final obtained materials are composed of pure cellulose. AFM and TEM obser...

Cocoa bean shells (CBS) are a by-product of the cocoa bean processing industry. They represent 12–20 wt% of dry cocoa beans, after having been separated from these by a roasting process. CBS often end up as a waste product which contains around 34 wt% of cellulose. The transformation of this waste into valuable and marketable products would help to...

New synthesis route of polysalt with single ion conductivity based on functionalization of polyacrylic acid is reported for all solid state lithium metal batteries. Poly[(trifluoromethyl)sulfonyl acrylamide] PA–LiTFSI was synthesized in two steps reaction. The degree of functionalization of the polymer backbone by anion of lithium salt bis(trifluor...

Two new cathode materials based on redox organosulfur polymers were synthesized and investigated for rechargeable lithium batteries as a proof-of-concept study. These cathodes offered good cycling performance owing to the absence of polysulfide solubility, which plagues Li/S systems. Herein, an aliphatic polyamine or a conjugated polyazomethine was...

Lithium-Sulfur (Li-S) battery technology is one of the promising candidates for next generation energy storage systems. Many studies have focused on the cathode materials to improve the cell performance. In this work we present a series of poly (S-DVB) copolymers synthesised by inverse vulcanization of sulfur with divinylbenzene (DVB). The poly (S-...

Li-S cell development at CIC Energigune

Li-S cell development at CIC Energigune

A novel approach based on the increase of the intrinsic oxidative stability of uncrosslinked membranes is addressed. The co-grafting of styrene with methacrylonitrile (MAN), which possesses a protected α-position and strong dipolar pendant nitrile group, onto 25 μm ETFE base film is disclosed. Styrene/MAN co-grafted membranes were compared to styre...

Radiation grafted membranes with controlled monomer content were prepared to investigate the role of nitrile containing comonomers on the properties of proton concluding membranes. The membranes consist of a partially fluorinated backbone of ETFE with grafted chains containing styrene sulfonic acid and its comonomer, methacrylonitrile (MAN) or acry...

A new membrane material for polymer electrolyte fuel cells (PEFC), ETFE-graft-poly(alpha-methylstyrene-sulfonic acid-co-methacrylonitrile), is presented, Its preparation by radiation-induced grafting and the dependence of the reaction kinetics on the irradiation dose (3 and 15 kGy) and crosslinker concentration are reported. A series of divinylbenz...

The influence of temperature and moisture activity on the viscoelastic behavior of fluorinated membranes for fuel cell applications was investigated. Uncrosslinked and crosslinked ethylene tetrafluoroethylene (ETFE)-based proton-conducting membranes were prepared by radiation grafting and subsequent sulfonation and their behavior was compared with...

We report on correlations between the proton conductivity, the water swelling and the dry-state morphology of ETFE-g-poly(sulfonated styrene-co-DVB) proton-exchange membranes (PEMs). We focus on the influence of the systematically varied monomer composition. Especially, the impact of the DVB cross-linker on the ion-rich phase aggregated in the dry...

The relationships between the nano-scale structure and the monomer composition of proton exchange membranes (PEMs) are reported. The PEMs are synthesized by preirradiation-induced grafting ETFE with styrene and cross-linker, 1,3-diisopropenylbenzene (DIPB), where the styrene moieties are sulfonated subsequently. The degree of grafting is constant,...

A novel crosslinked radiation grafted poly(ethylene-alt-tetrafluoroethylene) (ETFE) based membrane has been obtained by use of the crosslinker 1,3-diisopropenylbenzene (DIPB). The investigated membranes are based on 25 μm thick ETFE film grafted with styrene/DIPB. Grafted films and proton-exchange membranes with varying DIPB concentration and fixed...

The mechanical stability is, in addition to thermal and chemical stability, a primary requirement of polymer electrolyte membranes in fuel cells. In this study, the impact of grafting parameters and preparation steps on stress–strain properties of ETFE-based proton conducting membranes, prepared by radiation-induced grafting and subsequent sulphona...

An SANS investigation of hydrated proton exchange membranes is presented. Our membranes were synthesized by radiation‐induced grafting of ETFE with styrene in the presence of a crosslinker, followed by sulfonation of the styrene. The contrast variation method was used to understand the relationship between morphology, water uptake, and proton condu...

A small-angle neutron scattering (SANS) investigation of saturated aqueous proton exchange membranes is presented. Our membranes were synthesized by radiation-induced grafting of poly(ethylene-alt-tetrafluoroethylene) (ETFE) with styrene in the presence of crosslinker (divinylbenzene, DVB) and the polystyrene was sulfonated subsequently. The contra...

Styrene radiation grafted ETFE based proton conducting membranes are subject to degradation under fuel cell operating conditions and show a poor stability. Lifetimes exceeding 250h can only be achieved with crosslinked membranes. In this study, a novel approach based on the increase of the intrinsic oxidative stability of uncrosslinked membranes is...

In this study the effect of crosslinker (divinylbenzene (DVB)) content on the chemical stability of poly(ethylene-alt-tetrafluoroethylene) (ETFE) based membranes using an H 2 O 2 solution was carried out. Furthermore, the first long term-testing of single H 2 /O 2 cell over 2180h of an MEA assembled using an optimized ETFE-based membrane prepared b...

In this study, the effect of cross-linker content on the chemical stability of poly(ethylene-alt-tetrafluoroethylene) (ETFE)-based radiation-grafted and sulfonated membranes was investigated. An ex situ degradation test in H(2)O(2) solution showed a strong increase in stability of cross-linked membranes compared to uncross-linked ones. Excessive cr...

Selective exposures of poly(ethylene-alt-tetrafluoroethylene) (ETFE) films with hard X-rays through high aspect ratio Ni-masks were performed at the LIGA3 beamline of the “Angström Quelle Karlsruhe” (ANKA) to create patterns of radicals used as initiators for the grafting of styrene into the bulk of the ETFE films. Grafted films were then sulfonate...

Proton-exchange membranes are required to exhibit chemical, mechanical, and thermal stability for fuel cell applications. The present investigation has been carried out to explore the thermal behavior of poly(ethylene-alt-tetrafluoroethylene) (ETFE)-based proton-conducting membranes, both uncrosslinked and crosslinked, prepared by radiation graftin...

Crosslinked proton-exchange membranes were prepared by radiation-induced grafting of styrene into poly(ethylene-alt-tetrafluoroethylene) (ETFE) and subsequent sulfonation. The influence of the crosslinker, divinylbenzene (DVB), on various film and membrane properties was investigated in detail. A series of grafted films and membranes were prepared...