1,3-Divinyltetramethyldisiloxane (DTMS) is a multifunctional additive that is used to improves the cycling stability and capacity retention of Li-rich Mn-based layered oxide cathodes (LRMs). Cycling performance evaluations demonstrate that LRM/Li cells without the additive exhibit lower capacity retention. DTMS can significantly improve the capacity retention of LRM/Li cells from 42.8% to 75% at 0.5C. Theoretical calculations indicate that DTMS is preferentially oxidized on the LRM surface. Physical characterization results reveal that DTMS generates a layer on the LRM surface that is both less resistive and thinner than the LRM by reacting with HF/F− from the electrolyte. This DTMS-derived layer inhibits adverse reactions between the cathode and electrolyte, thus, effectively maintaining the cathode structure.

The electrode, where electrochemical reactions are taken place, plays a vital role in the overall performance of vanadium flow batteries (VFBs). In this paper, a composite of manganese oxide and amorphous carbon was first synthesized from metal-organic frameworks and used as a catalyst to promote the electrochemical behavior of electrodes. The newly proposed catalyst was fabricated by a carbonization process of Mn-based metal-organic framework obtained by hydrothermal method. The morphology, composition, electrochemical activity and cell performance are respectively studied. The results show that: i) the catalyst carbonized at 900 °C possesses a smaller size, larger specific surface area, more oxygen-containing functional group and realizes superior electrochemical activity; ii) it helps the vanadium flow battery to increase its energy efficiency by 6% at 100 mA cm−2; iii) it is also beneficial to the working voltage, discharge capacity, high current density property and cycling performance of VFBs. Thus, this work can not only provide a new type of electrochemical catalyst for vanadium flow batteries, but also be significant to the improvement of the overall performance and conducive to the widespread application of vanadium flow batteries.

Ni migrates from cermet fuel electrodes in SOECs at high overpotentials, prompting interest in alternative electrode materials. Ni-free perovskites with mixed ionic and electronic conductivity are being developed as substitutes for Ni-YSZ- or Ni-CGO-cermet fuel electrodes. However, some perovskite electrodes exhibit poor electrocatalytic activity during steam electrolysis. This study focuses on the synthesis, phase evolution, and cation oxidation state of Sr0.5Pr0.5MnO3 (SPM) perovskite under oxidizing and reducing atmospheres. The electrochemical performance of the SPM electrode is investigated at different steam concentrations (3–50% H2O in H2). Rietveld refinement reveals a phase transformation from Pm-3m (221) to I4/mmm (139) in humidified 5% H2 in N2 gas at 800 °C. XPS measurements indicate that the I4/mmm (139) structure contains more oxygen vacancies, enhancing ionic conductivity and electrocatalytic activity. At 610 ◦C, the SPM electrode with the Pm-3m (221) space group exhibits a low polarization resistance of 0.173 Ω cm2 in 50% H2O in H2 gas. However, forming a Ruddlesden-Popper structure increases polarization resistance at higher temperatures due to a low-frequency reaction. Overall, the SPM electrode shows promising electrocatalytic activity across a wide range of oxygen partial pressure, making it a potential fuel electrode in SOECs.

Sn shows high volume expansion corresponding to its high capacity, hindering cycle performance. To resolve the problem, studies are being conducted on alloying metal elements with the Sn anode. For an overall analysis or optimization of various alloying conditions, atomistic simulations are used to investigate the atomic scale structural evolution in Sn anodes during Na infusion.In the present study, we choose Cu, Mn, and Ni as candidate metal elements for alloying, considering the conditions of metal elements. Then, the clustering behavior of metal elements as sodium infuses into Sn-M (M = Cu, Mn, Ni) alloy is investigated using an atomistic simulation. We find that Sn-M alloy is stable in an amorphous solid solution, and as Na atoms infuse, a phase transformation occurs such that M elements are separated out, forming M clusters and a NaxSn amorphous phase, which eventually causes a reduction in volume. Finally, a diffusion simulation is also conducted for Na infusion into spherical Sn-M nanoparticles, to see if the alloying element decreases the Na diffusion rate severely. The comparison of volume reduction and Na infusion rate suggests that Cu is the best alloying element for the Sn base alloy anode materials.

Physico-chemical battery models are widely used in the design and simulation of lithium-ion batteries due to their physically descriptive modelling approach. The model accuracy highly depends on the accurate identification of model parameters, yet accurate and feasible model parameterisation with state-of-the-art experimental techniques is laborious, expensive and tied to inherent measurement and estimation errors. Multi-step voltage-based data-driven parameter identification techniques are widely adopted in the literature to tackle this challenge. However, impedance-based parameter identification schemes lack a similar level of detailed analysis. Therefore, we propose a novel multi-step electrochemical impedance spectroscopy (EIS) based data-driven parameter identification framework to identify kinetic parameters of a physico-chemical battery model utilising particle swarm optimisation featuring metaheuristic optimisation capabilities. The parameter optimisation framework is designed methodically to identify parameter clusters with distinct sensitivities to specific EIS impedance regions, significantly improving identification accuracy. The generic particle swarm optimisation is fused with nature-inspired Darwinian events cross-generating new particles using selected parents to improve the algorithm’s predictions. The proposed data-driven parameter identification framework is benchmarked under multiple cell operating conditions and achieves a voltage prediction improvement of 28% for constant current discharge and 65% for transient duty cycles compared to an experimentally derived parameter set from the literature.

Lithium-ion batteries (LiBs) market has emerged drastically, and the amount of obsolete or waste LiBs also increased. The present review discusses a variety of current technologies for the secondary utilization of used LiBs (echelon utilization) and recycling waste LiBs (direct recycling, hydrometallurgy, pyrometallurgy, bioleaching, and other alternative biological processes), with the goal of advancing waste LiBs recycling, especially in support of industrialization and recycling processes. A bibliometric analysis on the recycling of waste LiBs and their associated technologies carried out using VOSviewer software indicated that the biological techniques have not yet been developed as compared to direct, hydrometallurgical, and pyrometallurgical technologies. Furthermore, it provides a brief overview of advances in biological approaches, such as bioleaching, biosorption, and bio-electrochemical systems, towards the recovery of metals from waste LiBs. In this study, new directions for effective waste LiBs processing towards resource/waste management sustainability are also identified.

Solid oxide cells with La0.8Sr0.2MnO3/yttria-stabilized zirconia (LSM/YSZ) air electrodes exhibit accelerated performance degradation during electrolysis of hydrogen production. Under galvanic mode with a current density of 0.5 A/cm2, baseline electrolysis cells exhibit a rapid increase in resistance upon 200 h of operation and become utterly delaminated after 350 h at 800 °C. To prevent such catastrophic delamination, SrFe2O4-δ solutions are infiltrated into the LSM/YSZ air electrode of as-fabricated cell. Under the identical operation condition, SrFe2O4-δ infiltrated cells exhibit performance enhancement manifested by an immediate decrease in electrolysis operation voltage and reduction of both series and polarization resistance and sustainability of 900 h continuous electrolysis operation without delamination. Nanostructure examination reveals active interaction of the SrFe2O4-δ infiltrate with cells after calcination, Fe diffusion into the LSM backbones, and formation of nanoparticles on the surface of the backbones. During electrolysis, the nanoparticles maintain intact morphology and constant particle size, while there is continuous cation exchange between the nanoparticles and the backbone. The nanostructure origin of the increased electrolysis performance, reduced resistance, and increased durability induced by infiltration are discussed. The present study demonstrates a feasible and viable approach to preventing electrode delamination while increasing the durability of hydrogen production for electrolysis cells.

Polysulfides (LiPSs) shuttling significantly impedes the real application of lithium-sulfur (Li–S) batteries. Herein, nitrogen (N), vanadium (V)-co-doped MXene with N-doped carbon coating layer (denoted as CNVM) is prepared and then used as the interlayer material between cathode and commercial separator to suppress the shuttle effect of LiPSs. The doped heteroatoms alter the structure of MXene, enhancing the adsorption ability by providing enormous chemisorption sites for LiPSs and also accelerating the electron transfer. Meanwhile, the N-doped carbon coating further improves the electrical conductivity and raises the chemical affinity to LiPSs. Finally, enhanced electrochemical reaction kinetics and accelerated polysulfide conversion are obtained. Thus, the as-assembled Li–S batteries using the CNVM interlayer display high discharge capacity of 1373 mAh g−1 at 0.1 C, outstanding rate performance of discharge capacity up to 723 mAh g−1 at 3 C, long cycling life, as well as low average capacity degradation of 0.075% per cycle. Also, the practical application of the multifunctional CNVM-based interlayer is further manifested by the stable electrochemical performance even under a high sulfur loading of 7.2 mg cm−2 and decent service states of the as-assembled pouch cells.

All-solid-state batteries (ASSBs) using solid polymer electrolytes (SPEs) show a wide range of prospects in many aspects, but they do not perform well at high current densities. In order to solve the above problems, much effort has been spent on the improvement of electrolyte materials, but there is a lack of research on binders. This paper emphasizes the critical role played by the binder in the positive plates without any liquid infiltration,and an aqueous composite binder (CB) is designed by utilizing the characteristics of polyethylene oxide (PEO) and carboxymethyl cellulose lithium (CMC-Li) in lithium-ions transport. Electrochemical and Fourier transform infrared spectrometer (FTIR) tests demonstrate that the two polymers in the CB build a high-speed channel for migrating lithium-ions through synergistic action. The binder containing multiple reactive groups is tested to be highly competitive in both mechanical and electrochemical properties, which creates sufficient conditions for achieving high-performance ASSBs. The cells with CB as the binder are assembled which show a capacity of 65.5 mAh·g−1 at a current density of 3C while PVDF-based ASSBs exhibit only 3.3 mAh·g−1, and exhibit a capacity retention of 86.7% after 700 charge/discharge cycles at 0.5C (for comparison, PVDF-based ASSBs exhibit only 42.5%). This novel composite binder provides guidance for the further development of solid polymer batteries.

In-situ exsolution technique, as an efficient and controllable strategy of surface modification, has been extensively applied in reversible solid oxide cells (RSOCs). Here, we demonstrate LaxSrxTi0.9Ni0.1O3-δ fiber decorated by exsolved Ni nanoparticles and highlight the impacts of A-site deficiency on Ni exsolution and electrochemical performance of RSOCs. The La0.4Sr0.4Ti0.9Ni0.1O3 (A/B = 0.8) fibrous fuel electrode decorated by Ni nanoparticles with moderate Ni exsolution displays optimum electrochemical performance at 800 °C, achieving ∼540 mW cm−2 in SOFC mode and −0.742/0.385 A cm−2 under 1.3/0.7 V in RSOC mode. In contrast, high A-site deficiency (A/B < 0.8) allows heterogeneous phases (NiTiO3) and excessive Ni exsolution along with alterations of fibrous morphology, leading to slow gas diffusion, sluggish catalysis, and Ni agglomeration. The distribution of relaxation time (DRT) results show that the rate-limiting steps in symmetrical cells are gas diffusion, hydrogen adsorption, and dissociation, accounting for over 89% of the total RP. Ni-equilibrium model based on X-ray Rietveld refinement calculates the degree of exsolution with various A-site deficiency, revealing NiTiO3 is the key factor of excessive exsolution. Our work of high A-site deficiency exemplified here may serve in the design and nanoengineering of fibrous ABO3 perovskite oxides for RSOCs.

Though expensive platinum (Pt) is used as catalyst for oxygen reduction reaction (ORR) in polymer electrolyte fuel cells (PEFCs), insufficient durability remains as a bottleneck for commercialization of PEFCs. Improving both catalytic performance and durability by graphene encapsulation is an attractive strategy to solve this problem. In this study, graphene-encapsulated PtFe core-shell catalyst is synthesized with dimethyl formamide (DMF) and a pair of Pt and Fe electrodes without using any metal salts by utilizing the solution plasma (SP) process. TEM and EELS results show synthesized PtFe nanoparticles are encapsulated with close to single-layered highly crystallized graphene. Although commercial Pt/C showed significant performance degradation (ECSA −33%, MA −68%) after 50,000 cycles of accelerated durability test (ADT), PtFe core-shell catalyst shows remarkably improved durability (ECSA −13%, MA −19%) while graphene shell clearly remains. The improved durability is more prominent in the single cell test, the decrease in maximum power density after 6000 cycles of ADT was significantly lower as −1.2%, compared to that of Pt/C (−52.1%). This study introduces a novel and attractive catalyst synthesis process by the SP method followed by heat treatments and suggests graphene encapsulation can improve long-term durability of catalyst while maintaining ORR activity.

5G capable smart, lightweight, big-screen portable devices with a long standby time have growing demand as information and network technology developed. Lithium cobalt oxide, LiCoO2 (LCO) cathode material is extensively utilized in the portable electronics industry and needs further improvement. Here, a strategy to develop a high energy and high voltage 2 Ah (Amp-hour) LIBs (lithium-ion batteries) pouch cell is planned and excecated. The observed energy density of the designed cell is ∼248 Wh/kg (∼740 Wh/L) using graphite as a negative electrode and modified high voltage LCO (i.e., Li2CoMn3O8 (lithium cobalt manganese oxide) coated LCO), as a cathode with an areal capacity of ∼4.9 mAh/cm2. The developed pouch cells have cycled at a high rate (1C; up to 1000 cycles) and showed a minimum self-discharge rate (∼0.05% decay per day). An in-situ thermal mapping experiment and corresponding simulation analysis have been performed on the pouch cells at different charge and discharge stages to compare the thermal behavior. Furthermore, the effect of temperature on the SEI/CEI (solid electrolyte interface/cathode electrolyte interface) formation has been investigated by electrochemical impedance spectra (EIS) through MATLAB-based distribution of relaxation times (DRT) tool and understand different micro phenomena. The current approach may help in future generation LCO-based battery development.

Radical species generated during proton exchange membrane fuel cell operation considerably limit the achievable durability, particularly for heavy-duty vehicle applications. A promising solution to the problem is the incorporation of radical scavenger additives such as cerium which mitigates chemical attacks on the membrane. However, these additives migrate during fuel cell operation causing a loss in durability and performance due to detrimental interaction with various components of the fuel cell. Here, we study cation size selective agents as a means to immobilize cerium within perfluorosulfonic acid (PFSA) membranes. We synthesized an organometallic complex of cerium with 15-Crown-5 and investigated the effectiveness of this complex to immobilize cerium. Over 300% increase in cerium retention and an 80% increase in chemical durability were observed owing to the stabilization effect of crown ethers on cerium. Migration under a potential gradient can be eliminated while the complex also contributes to the enhancement in cerium radical scavenging activity. Current challenges with the proposed solution are highlighted and future work is discussed.

Proton exchange membrane fuel cells (PEMFCs) are considered as one of the most promising energy devices for transportations due to their high efficiency and cleanliness. However, metallic bipolar plates (BPPs), one of key components of PEMFCs, encounter an essential problem of insufficient durability. At present, the development of metallic BPPs is limited by the lack of scientific, efficient, and low-cost durability evaluation methods. We report a novel ex-situ accelerated durability evaluation method based on the quantitative analysis of PEMFCs voltage loss caused by the interfacial contact resistance (ICR) of metallic BPPs and the metal ions released from metallic BPPs. According to the in-situ evaluation (12000 h) results, the acceleration factor of proposed method is about 100. The availability and the accuracy of proposed method were verified by comparing the microstructure of metallic BPPs after in-situ and ex-situ test. It is of great significance for developing metallic BPPs with higher durability to establish such an ex-situ accelerated evaluation method.

Dry processing of lithium-ion battery electrodes facilely realizes the powder-to-film manner, which is thus regarded as a highly promising strategy for lithium-ion battery manufacturing. However, a fundamental understanding of the impact of the involved dry mixing is still rarely reported. Herein, the degree of dry mixing is monitored by the dry mixing time, and a set of dry-processed electrodes with different degree of dry mixing is accordingly prepared and comprehensively studied. This work novelly reveals that the degree of dry mixing exhibits pronounced impact on the morphology, the homogeneity of electrode components and the degree of PTFE fiberization, which leads to difference in the mechanical strength and electrochemical performance of dry-processed electrodes. Accordingly, it is suggested that a moderate degree of dry mixing is preferred for high-performance dry-processed lithium-ion battery electrodes.

Dual-ion batteries are being considered a feasible approach for electrochemical energy storage. In this battery technology both cations and anions are involved in the redox reactions, respectively, at the anode and the cathode. However, the participation of both ions in the redox reactions means that enough salt must be added in the electrolyte to ensure proper battery functioning, which present a limiting factor in battery design. Herein, a modified version of the standard pseudo-2D Doyle-Fuller-Newman model is proposed to account for the different redox reactions that occur in dual-ion batteries and simulate the variation of average salt concentration in the electrolyte during charging and discharging. The model has been validated against galvanostatic cycling and electrochemical impedance spectroscopy experimental data from dual-ion batteries based on poly(2,2,6,6-tetramethyl-1-piperidinyloxy methacrylate) (PTMA). Such a model can be helpful to design practical dual-ion batteries that respect the constraints imposed by their working mechanism and maximize the obtainable capacity and energy density.

Thermal runaway propagation (TRP) is the most challenging safety issue of lithium-ion battery systems. An early warning signal is promising for providing time to mitigate or prevent TRP and further disasters timely. This study investigates the strain characteristics of different format prismatic batteries during the TR/TRP processes, dividing the strain-changing trend into three stages according to the complex chemical composition interactions and TR features. Experimental results prove that the signal provides more than a 500s interval for a timely solution from the battery management system. Besides, the maximum strain increment (Δεmax)/capacity(Q)-Q equalization is quantitively analyzed. Moreover, Δεmax-Q and RI-Q equalizations are proposed to reveal the TR mechanical feature and guide the TR warning threshold definition of battery management systems (BMSs). Furthermore, the strain-changing trend and warning effect is also proved in TRP tests. TRP strain mechanism is unlocked from the mechanical deformation perspective. Battery deformation is opposite to the TRP direction, which guides accident analysis. This study proposes a cheap and reliable warning signal for an in-line configuration battery system, with only one strain gauge attached to the surface center of the first/last battery casing, which has more potential to guarantee the active safety of battery systems.

Battery anodes generally have a layered structure consisting of an active material layer (including binder, conductive carbon, and active material) and a foil layer of the current collector (copper foil). Such layered structures bring grand challenges to our understanding of the mechanical behaviors of the Si-based anode sheets since the large deformation of the Si particles, and solid-solid interfacial interactions (particle-particle and particle-binder) are key knowledge in high-energy, safe, and durable batteries. Herein, we characterize a typical commercialized Si-based anode with detailed microstructure morphology. Representative mechanical tests, including tensile and compression tests, are conducted to characterize the constitutive behaviors of the anode materials. Further, we propose a 3D computational model with detailed descriptions of the microstructures of the active material is established to enable a fundamental understanding of the deformation behaviors. Results present a comprehensive understanding of the Si-based anode materials for the first time and provide a powerful model for the future design of the anode for the next-generation batteries.

Solid oxide fuel cell (SOFC) technology offers reliable and efficient power generation from electrochemical oxidation of fuel gasses. State-of-the-art (SoA) anodes based on Ni cermets are prone to poisoning by fuel impurities, including sulfur. Next generation anode materials should be more robust towards sulfur poisoning e.g. in the event of failure or expiry of desulfurization units utilized in SOFC systems. Herein we present the performance and sulfur tolerance of short stacks with large area electrolyte supported cells with Ni:Ce0.8Gd0.2O1.9 (CGO) and FeNi:CGO co-infiltrated La0.4Sr0.4Fe0.03Ni0.03Ti0.94O3 (LSFNT) anodes tested under real-life conditions using reformed grid natural gas and an upstream, bypassable desulfurization unit. The initial performance at 750 °C and 850 °C was similar to a SoA cell with Ni/CGO cermet anode for both types of infiltrate. Bypassing the desulfurization unit led to a much lower performance loss compared to SoA. Additionally, the cells with LSFNT anodes showed almost complete recovery of performance after stopping the exposure to sulfur, whereas the reference SoA cell experienced some degree of irreversible degradation. Based on the promising initial performance and tolerance towards failure of desulfurization units, LSFNT anodes infiltrated with non-noble electrocatalysts are attractive candidates for next generation SOFC systems.

Proton exchange membranes (PEMs) have to be fabricated as thin as possible to minimize the ohmic loss in the cell voltage of proton exchange membrane fuel cells (PEMFCs) and water electrolyzers (PEMWEs). Additionally, the dimensional and mechanical stabilities of the PEMs must be maintained because they are critical for prolonging the cell lifespan in energy conversion devices that are used in moist environments. Herein, a sulfonated poly(p-phenylene)-based (SPP) multiblock ionomer is impregnated into a porous polytetrafluoroethylene (PTFE) substrate as a practical strategy for fabricating a mechanically robust and thin membrane. A five-layered structure is fabricated using two PTFE substrates as the composite membrane to increase the interfacial area between the SPP ionomer and PTFE; PTFE is treated with n-propyl alcohol to mediate the interfacial interactions between the two incompatible components. The composite membrane exhibits enhanced dimensional stability and mechanical properties compared with those of the pristine membrane owing to the SPP ionomer interlocking with PTFE. Regarding the electrochemical properties, the cell performance of the composite membrane displays a high current density of 1.52 A/cm2 at 0.5 V and 7.90 A/cm2 at 1.9 V for PEMFC and PEMWE, respectively; these densities are 32% and 16% greater, respectively, than that of Nafion212.