Sodium-ion batteries (SIBs) are among the most promising candidates for large-scale electrical energy storage devices owing to the low cost, abundance, and widespread of sodium resources. However, ...finding a suitable anode material is a critical necessity to uphold the commercialisation of SIBs. Herein, we report a facile synthesis process to prepare hard carbons derived from date palm biomass consisting of direct pyrolysis of seeds or pulp at different heat treatment temperatures in the range between 800 and 1400 °C. The electrochemical performances of the prepared hard carbons were investigated in SIBs and exhibited high reversible capacity of 300 mAh g−1 and promising initial coulombic efficiency (ICE) of 88.4%, which is the highest ICE reported for hard carbon materials to date. This work is the first to report a successful implementation of date palm as precursor to prepare low cost and high performance hard carbon anode materials for SIBs.
Display omitted
Considering the natural abundance and low cost of sodium resources, sodium‐ion batteries (SIBs) have received much attention for large‐scale electrochemical energy storage. However, smart structure ...design strategies and good mechanistic understanding are required to enable advanced SIBs with high energy density. In recent years, the exploration of advanced cathode, anode, and electrolyte materials, as well as advanced diagnostics have been extensively carried out. This review mainly focuses on the challenging problems for the attractive battery materials (i.e., cathode, anode, and electrolytes) and summarizes the latest strategies to improve their electrochemical performance as well as presenting recent progress in operando diagnostics to disclose the physics behind the electrochemical performance and to provide guidance and approaches to design and synthesize advanced battery materials. Outlook and perspectives on the future research to build better SIBs are also provided.
Room temperature sodium‐ion batteries show great promise for large scale electrochemical energy storage application because of the low cost and large abundance of sodium resource. The progress and main challenges regarding the development of electrode, electrolytes, and advanced diagnostics are summarized with the aim of achieving a high energy density of over 400 Wh kg−1 on the cell level.
Piezoelectric nanogenerators are attracting substantial attention due to the environmental constraints and ecological considerations of energy harvesting. However, the Achilles' heel of the majority ...of these nanogenerators is the presence of toxic compounds or the requirement of a poling process to promote higher piezoelectric effect. Here, a self-poled and bio-flexible piezoelectric nanogenerator (BF-PNG) is designed, based on lead-free biocompatible Ba0.85Ca0.15Zr0.10Ti0.90O3 nanoparticles that are functionalized with polydopamine and embedded in the polylactic acid biodegradable polymer. The BF-PNG can generate open-circuit voltage and short-circuit current of 14.4 V and 0.55 µA, respectively, under gentle finger tapping. Furthermore, it demonstrates an outstanding high mechanical robustness, stable and durable output even after one year. It achieves a maximum power density of about 7.54 mW/cm3 at a low resistive load of 3.5 MΩ. The feasibility of the BF-PNG by trigging commercial electronics such as charging capacitors and lighting a LED is verified, and the BF-PNG can drive a 1 µF capacitor to store the energy of 3.92 µJ within 115 s under gentle finger tapping. This research demonstrates that a lead-free piezoceramic in combination with a biodegradable piezopolymer can lead to a design of bio-flexible piezoelectric nanogenerators with outstanding performances and in particular useful in self-powered medical devices.
Display omitted
•Self-poled and bio-flexible piezoelectric nanogenerator (BF-PNG) based on BCZT bioceramic and PLA biopolymer.•The BF-PNG can generate Voc and Isc of 14.4 V and 0.55 µA, respectively, under gentle finger tapping.•High power density of 7.54 mW/cm3 at low resistive load of 3.5 MΩ is achieved.•The BF-PNG can charge capacitors and light an LED under gentle finger tapping.
Owing to the high abundance of sodium and its low cost compared to lithium, sodium ion batteries have recently attracted a renewed interest as possible candidates for stationary and mobile energy ...storage devices. Herein, we present a new sodium ion intercalation material, NaxCo2/3Mn2/9Ni1/9O2, which has been synthesized by a sol–gel route in air followed by a heat treatment at 800 °C for 12 h. Its structure has been studied by X-ray diffraction showing that the material crystallized in a P2-type structure (space group P63/mmc). As far as the electrochemical properties of NaxCo2/3Mn2/9Ni1/9O2 as positive electrode are concerned, this compound offers a specific capacity of 110 mAh g−1 when cycled between 2.0 and 4.2 V vs. Na+/Na. The electrodes exhibited a good capacity retention and a coulombic efficiency exceeding 99.4%, as well as a reversible discharge capacity of 140 mAh g−1 when cycled between 2.0 and 4.5 V. These results represent a further step towards the realization of efficient sodium ion batteries, especially considering that the synthesis method proposed here is simple and cost effective and that all the electrochemical measurements were carried out without any use of additives or any optimization for both the materials and the cell components.
•Na2/3Co2/3Mn2/9Ni1/9O2 by a sol gel method.•This layered material adopts the P2-type structure as revealed by the Rietveld analysis.•This cathode delivers a reversible discharge capacity of 110 mAh g−1 with an excellent capacity retention.•Up to 140 mAh g−1 could be reached if cycled between 2.0 and 4.5 V.
This work aims to study the production of Green Ammonia (Green-NH3) from a plant solely powered with Renewable Energy (RE) sources. The main current challenge of green ammonia plants is dealing with ...the energy intermittency and unpredictability of RE sources while ensuring a steady state ammonia production to avoid damaging the non-flexible Haber Bosch (HB) catalytic reactor. This work delivers a novel Techno-Economic (TE) modeling approach aiming to optimize the design and operation of a pilot-scale G-NH3 plant. The proposed TE model takes into consideration the intermittency of the RE sources, by considering different site locations with consistent yearly meteorological data. Additionally, to ensure a continuous power supply to the HB reactor, the model uses an original Energy Management Strategy (EMS) to adequately dispatch power available from the RE sources to Charge/Discharge Energy Storage Systems (ESS). The TE performances of the plant were evaluated by considering two main Key Performance Indicators (KPIs): HB Load Factor (LF) and Levelized Cost of Ammonia (LCOA). The results of this study indicated that the implemented EMS allowed to efficiently reduce the fluctuation of the RE sources by adequately allocating the available power to different time slots, which consequently increased the HB LF by 56% to 65%, depending on the type of the RE configuration. Consequently, this increase in the LF lead to a reduction of the overall cost of the plant, as the increase on production yield overweight the investment and operational costs increase. The PV/Battery scenario was found to be the most optimal plant entailing 6 MW of PV coupled to 11 MWh of Battery capacity with a LCOA of 774 $/tNH3. Finally, a forecast estimate projected between 2021 and 2050, predicted a potential cost reduction down to 250 $/tNH3, and suggests that by the year 2030, green ammonia is expected to be economically competitive with the conventional fossil-fuel based processes.
•An advanced modeling approach applied to GNH3 executing real meteorological data.•Impact of renewable energy intermittency on plant techno-economic performances.•PV/Battery using PEM electrolyzers is the optimal configuration with 775$/t NH3.•Green Ammonia is expected to be competitive against fossil-fuel by 2030.•Potential cost reduction of ammonia is estimated down to 250$/t by 2050.
Rechargeable sodium-ion batteries have recently attracted renewed interest as an alternative to Li-ion batteries for electric energy storage applications, because of the low cost and wide ...availability of sodium resources. Thus, the electrochemical energy storage community has been devoting increased attention to designing new cathode materials for sodium-ion batteries. Here we investigate P2- Na0.78Co1/2Mn1/3Ni1/6O2 as a cathode material for sodium ion batteries. The main focus is to understand the mechanism of the electrochemical performance of this material, especially differences observed in redox reactions at high potentials. Between 4.2 V and 4.5 V, the material delivers a reversible capacity which is studied in detail using advanced analytical techniques. In situ X-ray diffraction reveals the reversibility of the P2-type structure of the material. Combined soft X-ray absorption spectroscopy and resonant inelastic X-ray scattering demonstrates that Na deintercalation at high voltages is charge compensated by formation of localized electron holes on oxygen atoms.The inclusion of nickel and manganese in layered sodium metal oxide cathodes for sodium ion batteries is known to improve stability, but the redox behaviour at high voltage is poorly understood. Here in situ X-ray spectroscopy studies show that the redox behaviour of oxygen anions can account for an increase in specific capacity at high voltages.
The cathode material P2‐NaxCo2/3Mn2/9Ni1/9O2, which could be used in Na‐ion batteries, was investigated through synchrotron‐based hard X‐ray photoelectron spectroscopy (HAXPES). Nondestructive ...analysis was made through the electrode/electrolyte interface of the first electrochemical cycle to ensure access to information not only on the active material, but also on the passivation layer formed at the electrode surface and referred to as the solid permeable interface (SPI). This investigation clearly shows the role of the SPI and the complexity of the redox reactions. Cobalt, nickel, and manganese are all electrochemically active upon cycling between 4.5 and 2.0 V; all are in the 4+ state at the end of charging. Reduction to Co3+, Ni3+, and Mn3+ occurs upon discharging and, at low potential, there is partial reversible reduction to Co2+ and Ni2+. A thin layer of Na2CO3 and NaF covers the pristine electrode and reversible dissolution/reformation of these compounds is observed during the first cycle. The salt degradation products in the SPI show a dependence on potential. Phosphates mainly form at the end of the charging cycle (4.5 V), whereas fluorophosphates are produced at the end of discharging (2.0 V).
Don't stand idly by! Based on photoelectron spectroscopy results obtained on a synchrotron, the crucial role of the passivation layer present at the surface of a P2‐Nax(Co2/3Mn2/9Ni1/9)O2 cathode for use in Na‐ion batteries is described. This technique also enables the evolution of the oxidation state of the three transition metals to be followed; all are active during electrochemical cycling.
Anatase TiO
2
is prepared via a facile and eco-friendly synthesis method where titanium tetra isopropoxide and sodium alginate are used as the titanium precursor and templating agent, respectively. ...Structural characterization of the prepared sample via X-ray diffraction and Raman spectroscopies confirm the formation of nanoparticles Titanium Oxide with anatase type structure without impurities. Further morphological characterization of the material showed the spherical shape of the particles. The prepared TiO
2
has been studied as an anode material for lithium-ion batteries. TiO
2
electrodes have delivered a reversible capacity of 266 mAh g
−1
, 275 mAh g
−1
with coulombic efficiencies of 70%, 75% during the first cycle under C/10 current rate for TiO
2
calcined at 300 °C and 450 °C, respectively. The activity of Ti
4+
/Ti
3+
redox couple during the lithiation/delithiation process was evidenced using X-ray Photoelectron Spectrometry. The high capacity retention was maintained for 100 cycles. The prepared nanoparticles TiO
2
has prodigious potential for large scale production of anode materials for lithium-ion batteries.
Graphic abstract
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 biopolymers present an opportunity as an eco‐friendly material able to replace the conventional Nafion membrane in proton exchange membrane fuel cells (PEMFC). Chitosan and cellulose were the most studied in literature owing to their abundance in nature, low cost, and high affinity for water, which are sought‐after properties for PEM. In addition to that, their ease of modification through their hydroxyl or amine groups represents an opportunity to further enhance their characteristics and thus meet the criteria of diverse applications. The use of biopolymers as an adequate PEM is facing many challenges. Having a practical proton conductivity and securing the physicochemical stability of the biopolymers in fuel cell operating conditions are two of the most important challenges to overcome. Promising strategies to simultaneously address these challenges such as crosslinking, making interpenetrated networks, and making blends and composites are reported.
This review assesses the use of biopolymers in proton exchange membranes (PEMs) for fuel cell applications, focusing on the two most commonly studied biopolymers, chitosan and cellulose. It explores the various strategies employed with these biopolymers, such as modification, crosslinking, making interpenetrated networks, and using in blends or composites, aiming to improve membrane performance and meet PEM requirements.
Titanium oxyphosphate M0.5TiOPO4 (M=Ni, Cu, Fe) represent a promising candidate as an anode material for the lithium-ion batteries thanks to their good energetic performance and structural stability.
...In this work, we report on the high capacity of Co0.5TiOPO4/C electrode material. In particular, at C rate, the discharge capacity of more than 210mAh/g was maintained for 80 charge/discharge cycles. Furthermore, Co0.5TiOPO4/C composite exhibits excellent rate-capability with excellent coulombic efficiency. The outstanding electrochemical performance of Co0.5TiOPO4/C anode material might be attributed to its well crystallinity, controlled morphology due to the sol–gel preparation method, and the particles surface carbon-coating.
•Co0.5TiOPO4 anode material was prepared by the sol-gel method directly.•Co0.5TiOPO4/C composite exhibits a capacity of 210 mA h/g for 80 cycles.•An irreversible behavior occurs on the first discharge resulting from Co extrusion.•Both lithium insertion and conversion reaction were involved during the cycling.
PDF
