Batteries & Supercaps最新文献

Ceramic ion conductors play a pivotal role as electrolytes in solid-state batteries (SSBs). Aside from the ionic conductivity, their (electro)chemical stability has a profound effect on the performance. Lithium thiophosphates represent a widely used class of superionic materials, yet they suffer from limited stability and are known to undergo interfacial degradation upon battery cycling. Knowledge of composition-dependent properties is essential to improving upon the stability of thiophosphate solid electrolytes (SEs). In recent years, compositionally complex (multicomponent) and high-entropy lithium argyrodite SEs have been reported, having room-temperature ionic conductivities of σ_ion>10 mS cm⁻¹. In this work, various multi-cationic and -anionic substituted argyrodite SEs are electrochemically tested via cyclic voltammetry and impedance spectroscopy, as well as under operating conditions in SSB cells with layered Ni-rich oxide cathode and indium-lithium anode. Cation substitution is found to negatively affect the electrochemical stability, while anion substitution (introducing Cl⁻/Br⁻ and increasing halide content) has a beneficial effect on the cyclability, especially at high current rates.

Carbonate-based electrolytes generally suffer from low Coulombic efficiency and poor cycling stability in lithium metal batteries. In this work, localized high concentration electrolytes (LHCEs) based on dimethyl carbonate (DMC) with varying diluent additions are designed. LHCEs demonstrate higher Li⁺ transference numbers and a greater proportion of contact ion pairs (CIPs) and ion pair aggregates (AGGs) in the solvation structures, facilitating the formation of anion-derived solid electrolyte interphase (SEI). Furthermore, LHCEs enhance the Coulombic efficiency of Li||Cu cells and improve the anodic stability against lithium. One of these LHCEs, prepared with appropriate diluent addition, exhibits excellent capacity retention in Li||NCM622 cells at 0.5 C after 150 cycles, thus presenting promising possibilities for the development of high energy density lithium metal batteries.

Metal sulfides materials are promising anode candidates for Na⁺ storage due to their low cost and high theoretical capacity, while the complex phase transition and inevitable volume expansion during cycling restrain their practical applications. Herein, a simple one-pot manipulation strategy was designed to construct Co₉S₈ nanoparticles strongly encapsulated in carbon nanotubes (Co₉S₈@C/NTs) composite structure with enhanced structural stability and reaction kinetics, resulting in greatly improved Na⁺ storage performance. Specifically, the obtained Co₉S₈@C/NTs could exhibit a remarkable capacity of 500 mAh g⁻¹ at 0.5 A g⁻¹ after 100 cycles and exceptional cycling stability over 600 cycles with 88 % capacity retention at 1 A g⁻¹. Furthermore, the theoretical calculations combined with systematic characterizations confirm that the strong interaction between Co₉S₈ and the carbon matrix could greatly enhance the Na⁺ adsorption ability and facilitate the electron transfer dynamics for superior Na⁺ storage capability. More importantly, the full cell device can deliver an outstanding energy density of 144.32 Wh kg⁻¹ and a decent cycling life with 82 % capacity retention of almost 100 cycles at 0.1 A g⁻¹. This work could provide more valuable insights for designing advanced metal sulfide nanocomposites and demonstrate fascinating prospects for commercial application.

Invited for this month's cover picture is the Balducci's group who works on the development of innovative electrolytes and materials for safer, high-performance supercapacitors and batteries, and on advanced real-time characterization techniques to improve the understanding of aging and charge storage processes in electrochemical devices. The front cover illustrates a supercapacitor evaluated with the screening technique presented in this report. It highlights different electrolyte compositions, indicated by chemical compounds above the setup. This approach provides insights into how capacitance, energy, power, entropy, and enthalpy respond to changes in temperature and voltage. Read the full text of the Research Article at 10.1002/batt.202300581.

The Cover Feature illustrates the silicon-air batteries, powered by silicon, as a groundbreaking solution for energizing transient electronics. By incorporating partial self-destruction mechanisms, they enhance data security and impose a controlled device lifespan. After being used as the energetic fuel, silicon can turn into silica sand, completing its life cycle. This innovative application seamlessly integrates energy storage and electronics, offering practical advancements in technology and data security. More information can be found in the Research Article by Y. E. Durmus and co-workers.

The Front Cover illustrates a supercapacitor evaluated with the screening technique. It highlights different electrolyte compositions, indicated by chemical compounds above the setup. This approach provides insights into how capacitance, energy, power, entropy, and enthalpy respond to changes in temperature and voltage. More information can be found in the Research Article by F. A. Kreth and co-workers.

Electrolyte design is the optimal strategy to achieve extremely low temperature operation of lithium-ion batteries. Here, the diffusion coefficient of Li⁺ is proposed to improve the ion transport kinetics at low temperatures. The diffusion coefficient of Li⁺ is improved by constructing a Li⁺ solvation sheath with weak steric effects. Specifically, high binding energy BF₄⁻ anions are added to a 1 M LiPF₆ in propyl acetate (PA) electrolyte. Since the binding energy of Li⁺ with BF₄⁻ is greater than that of PA. Therefore, the small-sized BF₄⁻ replaces the large-sized PA molecule to form a Li⁺ solvation sheath with a weak steric effect, which increases the diffusion coefficient of Li⁺. Using the high diffusion coefficient electrolyte, the 800 mAh pouch cell retain 91 % and 75 % of its room temperature capacity at −40 °C(0.5 C rate) and −60 °C (0.2 C rate), respectively. And it also shows stable cycling at −40 °C. This work provides a new strategy for designing low-temperature electrolytes of lithium-ion batteries.

In this study we demonstrate detection of redox peaks in Li-ion pouch cells during cyclic voltammetry (CV), via the optical signal of plasmonic based fibre optic sensors placed inside Li-ion pouch cells. The sensors are placed inside the pouch cells during manufacture, allowing diagnostic data to be obtained from directly inside the cells in real time. We further present data showing the battery cell remains agnostic to the presence of fibre optic sensors over repeated cycling through analysis of the formation cycles, electrochemical impedance spectroscopy (EIS) analysis, coulombic efficiency data, capacity data and post-mortem materials analysis. This study provides evidence of the utility of fibre optic based diagnostic sensors, and in particular the novel use of plasmonic based fibre optic sensors, as an in situ battery diagnostic technique and potential research tool to investigate battery cell phenomena.

With advantages including high capacity, intrinsic safety and low cost, aqueous zinc-ion batteries (AZIBs) are ideal electrochemical energy storage devices for large-scale and portable energy storage. However, the development of AZIBs suffers from tricky challenges, such as the notorious Zn dendrite growth and severe parasitic reactions. Herein, as a low-cost and nontoxic biomass, agar is adopted to construct an interface layer on Zn foil to mitigate side reactions and induce uniform Zn deposition on Zn anodes. The interaction between Zn²⁺ and polar functional groups of agar can regulate Zn²⁺ distribution and promote Zn²⁺ desolvation, thus simultaneously achieving homogenous Zn deposition and suppressed hydrogen evolution reaction. Meanwhile, SO₄²⁻ anions are blocked from contacting Zn surface due to electrostatic repulsion, greatly restraining corrosion and passivation. Consequently, Zn||A-Cu asymmetric cell operates normally for 590 cycles with an average coulombic efficiency of 99.5 %, suggesting good reversibility of Zn plating/stripping. Notably, A-Zn symmetric cell exhibits a long lifespan of 1100 h at 2 mA cm⁻². Furthermore, the A-Zn||NVO full cell displays a superb capacity retention of 94.8 % after 3600 cycles at 5 A g⁻¹. This work offers a novel interface modification method for constructing stable and dendrite-free anodes of AZIBs.

Sodium superionic conductor (NASICON)-type cathode materials are considered promising candidates for high-performance sodium-ion batteries (SIBs) because of the abundance and low cost of raw materials. However, NASICON-type cathodes suffer from low capacities. This limitation can be addressed through the activation of sodium-excess phases, which can enhance capacities up to theoretical values. Thus, this paper proposes the use of transition metal (TM)-substituted Na₃V₂(PO₄)₂F₃ (NVPF) to induce sodium-excess phases. To identify suitable doping elements, an inverse design approach is developed, combining machine learning prediction and density functional theory (DFT) calculations. Graph-based neural networks are used to predict two crucial properties, i. e., the structural stability and voltage level. Results indicate that the use of TM-substituted NVPF materials leads to about 150 % capacity enhancement with reduced time and resource requirements compared with the direct design approach. Furthermore, DFT calculations confirm improvements in cyclability, electronic conductivity, and chemical stability. The proposed approach is expected to accelerate the discovery of superior materials for battery electrodes.