Michel Armand

• PhD
• Professor Emeritus at University of Picardie Jules Verne

Currently, electrolyte design for sodium‐based batteries is largely inherited from their lithium‐based counterparts, which often present critical challenges that hinder forging new perspectives and thus further improvements. This work delves into the key properties of representative sodium and lithium‐based electrolytes, encompassing prevailing sal...

Currently, electrolyte design for sodium‐based batteries is largely inherited from their lithium‐based counterparts, which often present critical challenges that hinder forging new perspectives and thus further improvements. This work delves into the key properties of representative sodium‐ and lithium‐based electrolytes, encompassing prevailing sa...

Li-metal-based batteries are considered as the next alternative to Li-ion batteries owing to their high specific capacity and energy density. Alleviating the use of liquid electrolytes, solid-state batteries using polymer electrolytes have gained vast attention. However, Li-metal solid-state batteries have major concerns regarding the non-total sup...

Lithium carbon fluoride (Li°∥CFx) batteries are the research hotspot amid the existing primary battery technologies, owing to their inherent safety and exceptionally theoretical energy density. From the perspective of bimolecular nucleophilic substitution (SN2) reactions for the conversion process of CFx electrode, we herein delve into the impact o...

Ionic Liquids (ILs) have received a substantial interest from the scientific community over the past few decades ¹ , in particular, because of their possible use as electrolytes for battery technology. This wide excitement stems from their known thermal stability and non-volatile nature ² (as opposed to more traditional organic carbonate-based elec...

Solid polymer electrolytes (SPEs) have been treated as a viable solution to build high‐performance solid‐state lithium metal batteries (SSLMBs) at the industrial level, bypassing the safety and energy density dilemmas experienced by today's lithium‐ion battery technology. To promote a wider application of SPEs‐based SSLMBs, the chemical and electro...

Differential capacitance measurements are known to provide vital information regarding electrical double layer charging as well as interfacial structuring of ionic liquids and ionic liquid-based electrolytes. Several hurdles have prevented these types of measurements from becoming widely used, including the fact that there exists no real consensus...

The extremely high chemical reactivity of lithium metal (Li°) electrodes and its enormous volume change during repetitive cycles cause continuous interfacial degradations in prevailing organic electrolytes, thus deteriorating the cycling performances of rechargeable lithium metal batteries (LMBs). Herein, departing from traditional wisdom on the de...

Li6PS5Cl (LPSCl) argyrodites offer high room temperature ionic conductivity (>1 mS cm⁻¹) and are among the most promising solid electrolytes. However, their chemical instability against Li metal compromises the long‐term cyclability. Using PEO‐LiTFSI as an interlayer or as a matrix for composite electrolytes is a promising strategy to address this...

Non‐aqueous electrolytes, generally consisting of metal salts and solvating media, are indispensable elements for building rechargeable batteries. As the major sources of ionic charges, the intrinsic characters of salt anions are of particular importance in determining the fundamental properties of bulk electrolyte, as well as the features of the r...

Polymer-in-salt electrolytes offer a promising solution to the critical challenge of low Li-ion conductivity in solvent-free solid polymer electrolytes. One crucial aspect of their development is maintaining good stability and high conductivity of molten salts within a polymer system. Remarkably, cationic poly(ionic liquids) (polyIL) have emerged a...

The effective flow of electrons through bulk electrodes is crucial for achieving high-performance batteries, although the poor conductivity of homocyclic sulfur molecules results in high barriers against the passage of electrons through electrode structures. This phenomenon causes incomplete reactions and the formation of metastable products. To en...

The minimization of irreversible active lithium loss stands as a pivotal concern in rechargeable lithium batteries, particularly in the context of grid‐storage applications, where achieving the utmost energy density over prolonged cycling is imperative to meet stringent demands, notably in terms of life cost. Departing from conventional methodologi...

There is an increasing demand to improve battery safety and performance as part of the global push to convert the small electronics and transportation sector to infrastructures based on electricity. This work follows the deposition of lithium metal in anode‐less conditions by an operando optical microscope using a transparent indium tin oxide‐polye...

The development of the most promising next-generation Lisingle bondS batteries with an improved cyclability is one of the greatest challenges nowadays. In this sense, here, a novel imidazolium-based polymeric ionic liquid (PVI10Cl) was successfully synthesized and integrated into a high-performing sulfur cathode. The lithium polysulfide trapping ab...

Among existing electrochemical energy storage technologies, lithium carbon fluoride (Li°||CFx) batteries have captured enormous attention owing to their surprisingly high energy density and low self-discharge rate. The features of nonaqueous...

Energy storage plays, undoubtedly, a fundamental role in the process of total decarbonization of the global economy that is expected to take place in the coming decades. The energy transition to a renewable and sustainable generation will be the solution to reduce greenhouse gas emissions and thus achieve the European Commission´s goal of becoming...

The incentives for the use of lithium metal negative electrode are easily justified considering the gain in energy density. Polymer electrolytes disclosed almost fifty years ago are still considered as an option for the most thought-for all solid-state systems. In fact, the only solid-state batteries commercialised are those from Blue Solutions® po...

Lithium garnets are considered as promising solid–state electrolytes for next–generation solid–state Li metal batteries (SSLBs). However, the Li intrusion driven by external stack pressure triggers premature of Li metal batteries. Herein, for the first time, we report an in situ constructed interfacial shield to efficiently inhibit the pressure–ind...

Aqueous Zn metal batteries are considered as competitive candidates for next‐generation energy storage systems due to their excellent safety, low cost and environmental friendliness. However, the inevitable dendrite growth, severe hydrogen evolution, surface passivation and sluggish reaction kinetics of Zn metal anodes hinder the practical applicat...

The growing requirements for electrified applications entail exploring alternative battery systems. Lithium‐sulfur batteries (LSBs) have emerged as a promising, cost‐effective, and sustainable solution; however, their practical commercialization is impeded by several intrinsic challenges. With the aim of surpassing these challenges, the implementat...

Li metal secondary batteries known for their high energy and power density are the much-awaited energy storage systems owing to the high specific capacity of Li metal. However, due to the instability of Li metal with common Li-ion battery electrolytes, a combination with a polymer electrolyte seems to be an effective strategy to alleviate the safet...

Hybrid solid electrolytes (HSEs), namely mixtures of polymer and inorganic electrolytes, have supposedly improved properties with respect to inorganic and polymer electrolytes. In practice, HSEs often show ionic conductivity below expectations, as the high interface resistance limits the contribution of inorganic electrolyte particles to the charge...

The current high-energy lithium metal batteries are limited by their safety and lifespan owing to the lack of suitable electrolyte solutions. Here we report a synergy of fluorinated co-solvent and gelation treatment by a butenoxycyclotriphosphazene (BCPN) monomer, which facilitates the use of ether-based electrolyte solutions for high-energy lithiu...

Next- Generation Lithium(Li)-based rechargeable battery technologies utilising silicon (Si) and Si-containing (Si/Gr, SiO x /Gr, SiN x etc.) anodes coupled with high-capacity/high-voltage insertion-type cathodes (IC) have gained significant attention from both academic and industrial sectors. ¹ This originates from their practically achievable high...

Before the debut of lithium-ion batteries (LIBs) in the commodity market, solid-state lithium metal batteries (SSLMBs) were considered promising high-energy electrochemical energy storage systems before being almost abandoned in the late 1980s because of safety concerns. However, after three decades of development, LIB technologies are now approach...

Sulfonimide salts are of great interest for battery use thanks to their special properties including sufficient superior chemical/thermal stabilities, structural flexibility, etc. In particular, the hydrogen-containing sulfonimide (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide anion {[N(SO2CF2H) (SO2CF3)]⁻, DFTFSI⁻}, stands out owing to i...

Despite the efforts devoted to the identification of new electrode materials with higher specific capacities and electrolyte additives to mitigate the well-known limitations of current lithium-ion batteries (LIBs), this technology is believed to have almost reached its energy density limit. It suffers also of a severe safety concern ascribed to the...

Rechargeable room-temperature sodium–sulfur (Na–S) and sodium–selenium (Na–Se) batteries are gaining extensive attention for potential large-scale energy storage applications owing to their low cost and high theoretical energy density. Optimization of electrode materials and investigation of mechanisms are essential to achieve high energy density a...

This paper provides a holistic view of the different studies related to gassing in NMC/graphite lithium-ion batteries over the past couple of decades of scientific development. It underlines the difficulty of predicting the concentration and the proportion of gas released upon cycling and storage and to get a clear mechanistic insight into the redu...

Gel polymer electrolytes (GPEs) are emerging as suitable candidates for high-performing lithium-sulfur batteries (LSBs) due to their excellent performance and improved safety. Within them, poly(vinylidene difluoride) (PVdF) and its derivatives have been widely used as polymer hosts due to their ideal mechanical and electrochemical properties. Howev...

Room temperature sodium sulfur (RT Na‐S) batteries with high theoretical energy density and low cost have recently gained extensive attention for potential large‐scale energy storage applications. However, the shuttle effect of sodium polysulfides is still the main challenge that leads to poor cycling stability, which hinders the practical applicat...

The increasing demand for electrical energy storage makes it essential to explore alternative battery chemistries that overcome the energy-density limitations of the current state-of-the-art lithium-ion batteries. In this scenario, lithium-sulfur batteries (LSBs) stand out due to the low cost, high theoretical capacity, and sustainability of sulfur...

Flexible zinc‐air batteries are based on gel polymer electrolytes (GPE), soft, semi‐solid components devoted to liquid electrolyte retention, ion conduction, and mechanical stability. Many synthetic polymers, and their blends, have been used in early works due to the good compromise between ionic conductivity, electrolyte retention, and mechanical...

Battery energy storage plays a pivotal role in the current energy transition due to exponential growth of the energy sector. Excess energy produced in the grid and increasing renewable energy production require efficient energy storage system to be developed. The development of such energy storage systems requires efficient materials screening, pro...

Rechargeable lithium metal polymer batteries (LMPBs) utilizing solid polymer electrolytes (SPEs) have gained increasing attention during the past five decades, owing to the superior flexibility, good process‐ability, and no‐leakage of SPEs versus traditional non‐aqueous liquid and inorganic solid electrolytes. Undoubtedly, among all of the SPE comp...

The advent of Li-metal batteries has seen progress toward studies focused on the chemical modification of solid polymer electrolytes, involving tuning either polymer or Li salt properties to enhance the overall cell performance. This study encompasses chemically modifying simultaneously both polymer matrix and lithium salt by assessing ion coordina...

Solid-state polymer electrolytes are considered as an alternative to classic liquid electrolytes, particularly for application in high-energy lithium metal batteries. With respect to common dual-ion conductors, single-ion conducting polymer electrolytes (SIC-PEs) are less affected by lithium dendrites growth and thus are particularly interesting fo...

Coulombic efficiency (CE) should be recognized as a key battery parameter since values lower than 98% are indicative of a significant loss in battery performance. CE is directly impacted by the production process in terms of speed and duration. Thus, this work reveals that regardless of the initial CE of the cell, the slurry mixing time of the PEO-...

Solid electrolytes are renowned for their nonflammable, dendrite-blocking qualities, which also exhibit stability over large potential windows. NASICON-type Na1+xZr2SixP3-xO12 (NZSP) is a well-known solid electrolyte material for sodium metal batteries owing to its elevated room temperature sodium-ion (Na⁺) conductivity and good electrochemical sta...

Densification of ceramic electrolytes is a key enabler in producing electrolyte pellets for solid-state batteries. This requires understanding the correlation between the starting grain size of electrolytes, chemical phase evolution and degree of compaction which determine ion conductivity and chemical stability of solid electrolytes. In our work w...

Solid-state lithium metal batteries (SSLMBs) are considered an auspicious technology to develop high energy density and safe energy storage devices. The double layer polymer electrolyte (DLPE) is a rational approach for engineering high-performance SSLMBs addressing electrolyte requirements with specifically designed polymers at the positive electr...

Rechargeable magnesium batteries (RMBs) have been considered as one of the most viable battery chemistries amongst the “post” lithium‐ion battery (LIB) technologies owing to their high volumetric capacity and the natural abundance of their key elements. The fundamental properties of Mg‐ion conducting electrolytes are of essence to regulate the over...

Since the oil crisis in the 1970s, the importance of rechargeable batteries has been noted by academia and industrial sectors. This becomes more prominent with increasing demand in e-mobility and...

Rechargeable magnesium batteries (RMBs) have been considered as one of the most viable battery chemistries amongst the “post” lithium‐ion battery (LIB) technologies owing to their high volumetric capacity and natural abundance of the key elements. The fundamental properties of Mg‐ion conducting electrolytes are of essence to regulate the overall pe...

Motivated by the request to build shape-conformable flexible, wearable and customizable batteries while maximizing the energy storage and electrochemical performances, additive manufacturing (AM) appears as a revolutionary discipline. Battery components such as electrodes, separator, electrolyte, current collectors and casing can be tailored with a...

Recycling lithium from spent batteries is challenging because of problems with poor purity and contamination. Here, we propose a green and sustainable lithium recovery strategy for spent batteries containing LiFePO4, LiCoO2, and LiNi0.5Co0.2Mn0.3O2 electrodes. Our proposed configuration of “lithium-rich electrode || LLZTO@LiTFSI+P3HT || LiOH” syste...

Rechargeable lithium-based batteries built with high-energy anode materials (e.g., silicon-based and silicon-derivative materials) are considered a feasible solution to satisfy the stringent requirements imposed by emerging markets, including electric vehicles and grid storage, due to their higher energy density compared to contemporary lithium-ion...

Polymer electrolytes provide a safe solution for all-solid-state high energy density batteries. Materials that meet the simultaneous requirement of high ionic conductivity and high transference number remain a challenge, in particular for new battery chemistries beyond Lithium such as Na, K and Mg. Herein, we demonstrate the versatility of a polyme...

Solid-state batteries are the holy grail for the next generation of automotive batteries. The development of solid-state batteries requires efficient electrolytes to improve the performance of the cells in terms of ionic conductivity, electrochemical stability, interfacial compatibility, and so on. These requirements call for the combined propertie...

Rechargeable lithium metal batteries (LMBs) are deemed as a viable solution to improve the power and/or energy density of the contemporary lithium‐ion batteries (LIBs). However, poor Li‐ion diffusivity within high‐energy cathodes causes sluggish kinetics of the corresponding redox reactions particularly at high C‐rates, thereby largely impeding the...

From the literature overview, lithium difluorophosphate salt, LiPO2F2, is considered a powerful electrolyte additive capable of enhancing lithium-ion batteries’ capacity retention. Lower cell impedance associated with SEI and/or CEI layers composition and texture modifications had been widely demonstrated, but without providing clear mechanisms. Th...

Polymer electrolytes (PEs) with excellent flexibility, processability, and good contact with lithium metal (Li°) anodes have attracted substantial attention in both academic and industrial settings. However, conventional poly(ethylene oxide) (PEO)-based PEs suffer from a low lithium-ion transference number (TLi+), leading to a notorious concentrati...

The increasing demand for electrical energy storage requires the exploration of alternative battery chemistries that overcome the limitations of the current state‐of‐the‐art lithium‐ion batteries. In this scenario, lithium‐sulfur batteries stand out for their high theoretical energy density. However, several inherent limitations still hinder their...

Undesired chemical degradation of lithium hexafluorophosphate (LiPF6) in non-aqueous liquid electrolytes is a Gordian knot in both science and technology, which largely impedes the practical deployment of large-format lithium-ion batteries (LIBs) in emerging applications (e.g., electric vehicles). From a fresh perspective that the decomposition of...

The inherent properties of non-aqueous electrolytes are highly associated with the identity of salt anions. To build highly conductive and chemically/electrochemically robust electrolytes for lithium-ion batteries (LIBs) and rechargeable lithium metal batteries (RLMBs), various kinds of weakly coordinating anions have been proposed as counterparts...

Future rechargeable Li metal batteries (LMBs) require a rational electrolyte design to stabilize the interfaces between the electrolyte and both the lithium metal anode and the high voltage cathode. This remains the greatest challenge in achieving high cycling performance in LMBs. We report an ether-aided ionic liquid electrolyte which offers super...

Comb‐like polymers are one of the most auspicious candidates for building fully amorphous and highly conductive solid polymer electrolytes (SPEs), which are essential components to develop high‐performance solid‐state rechargeable lithium metal batteries (RLMBs). Herein, two kinds of comb‐like polymers containing either polymethacrylate or polyacry...

Li-S batteries, as the most promising post Li-ion technology, have been intensively investigated for more than a decade. Although most previous studies have focused on liquid systems, solid electrolytes, particularly all-solid-state polymer electrolytes (ASSPEs) and quasi-solid-state polymer electrolyte (QSSPEs), are appealing for Li-S cells due to...

Rechargeable Li-based battery technologies utilising silicon, silicon-based, and Si-derivative anodes coupled with high-capacity/high-voltage insertion-type cathodes have reaped significant interest from both academic and industrial sectors. This stems from their practically achievable energy density, offering a new avenue towards the mass-market a...

Solid-state Lithium-metal batteries based on polymer electrolytes hold the most promising prospect to face energy density and safety issues encountered by conventional Li-ion batteries. The use of two different polymers, one for the cathode and another one as electrolyte, brings a sufficient energy gap and chemical stability allowing compatibility...

The use of gel polymer electrolytes (GPEs) is of great interest to build high-performing rechargeable lithium metal batteries (LMBs) owing to the combination of good electrochemical properties and improved safety. Herein, we report a facile and scalable one-pot preparation method of a GPE based on highly safe polyethylene glycol dimethyl ether (PEG...

The current Li-based battery technology is limited in terms of energy contents. Therefore, several approaches are considered to improve the energy density of these energy storage devices. Here, we report the combination of a heteroatom-based gel polymer electrolyte with a hybrid cathode comprising of a Li-rich oxide active material and graphite con...

The significant impact of the process steps on the electrode performance is one of the least developed aspects in the field of solid‐state batteries despite being a key issue for the transference of lab scale developments to production scale. To demonstrate that the knowledge of production parameters is essential, a set of high active material load...

Originating from “rocking‐chair concept”, lithium‐ion batteries (LIBs) have become one of the most important electrochemical energy storage technologies, which have largely impacted our daily life. The utilization of electrolyte additives in small quantities (≤5% by wt or vol) has been long viewed as an economical and efficient approach to regulate...