Recent Developments of Nanomaterials and Nanostructures for High-Rate Lithium Ion Batteries

Nanomaterials for Energy Storage Systems-A Review

The ever-increasing global energy demand necessitates the development of efficient, sustainable, and high-performance energy storage systems. Nanotechnology, through the manipulation of materials at the nanoscale, offers significant potential for enhancing the performance of energy storage devices due to unique properties such as increased surface area and improved conductivity. This review paper investigates the crucial role of nanotechnology in advancing energy storage technologies, with a specific focus on capacitors and batteries, including lithium-ion, sodium-sulfur, and redox flow. We explore the diverse applications of nanomaterials in batteries, encompassing electrode materials (e.g., carbon nanotubes, metal oxides), electrolytes, and separators. To address challenges like interfacial side reactions, advanced nanostructured materials are being developed. We also delve into various manufacturing methods for nanomaterials, including top-down (e.g., ball milling), bottom-up (e.g., chemical vapor deposition), and hybrid approaches, highlighting their scalability considerations. While challenges such as cost-effectiveness and environmental concerns persist, the outlook for nanotechnology in energy storage remains promising, with emerging trends including solid-state batteries and the integration of nanomaterials with artificial intelligence for optimized energy storage.

Transition metal phosphide-based oxygen electrocatalysts for aqueous zinc-air batteries

Electrically rechargeable zinc-air batteries (ZABs) are emerging as promising energy storage devices in the post-lithium era, leveraging the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) at the air cathodes. Efficient bifunctional oxygen electrocatalysts, capable of catalyzing both the ORR and OER, are essential for the operation of rechargeable ZABs. Traditional Pt- and RuO2/IrO2-based catalysts are not ideal, as they lack sufficient bifunctional ORR and OER activity, exhibit limited long-term durability, require high overpotentials and are expensive. In contrast, non-precious metal-based catalysts, including transition metal phosphides (TMPs), have gained significant attention for their promising bifunctional catalytic properties, making them attractive candidates for ZABs. Despite encouraging lab-scale achievements, translating these advancements into market-ready applications remains challenging due to suboptimal energy performance. Rationally engineered bifunctional TMPs hold great potential for overcoming these challenges and meeting the requirements of rechargeable ZABs. This feature article reviews recent progress in the development of TMP-based catalysts for ZABs, providing a comprehensive overview of ZAB fundamentals and strategies for catalyst design, synthesis, and engineering. A particular emphasis is placed on widely studied bifunctional Fe, Co, and Ni phosphides, along with approaches to enhance their catalytic performance. Key performance metrics are critically evaluated, including the potential gap (ΔE) between the ORR and the OER, specific capacity, peak power density, and charge-discharge cycling stability. Finally, this feature article discusses the challenges faced in TMP-based ZABs, proposes strategies to address these issues, and explores future directions for improving their rechargeability to meet the demands of commercial-scale energy storage technologies.

An alternate synthetic pathway to nanoscopic Li2FeS2 for energy storage

Lithium-rich iron sulphide, Li2FeS2, exhibits reversible charge-storage via both cationic and anionic sites, storing nearly 400 mA h g-1, but its synthesis is limited to solid-state methods that result in large primary particles. We describe an alternate solution-based, redox-mediated method to lithiate pyrite FeS2, ultimately forming nanoscale Li2FeS2.

Revolutionizing energy storage: exploring the nanoscale frontier of all-solid-state batteries

Due to their distinctive security characteristics, all-solid-state batteries are seen as a potential technology for the upcoming era of energy storage. The flexibility of nanomaterials shows enormous potential for the advancement of all-solid-state batteries' exceptional power and energy storage capacities. These batteries might be applied in many areas such as large-scale energy storage for power grids, as well as in the creation of foldable and flexible electronics, and portable gadgets. The most difficult aspect of creating a comprehensive nanoscale all-solid-state battery assembly is the task of decreasing the particle size of the solid electrolyte while maintaining its excellent ionic conductivity. Materials possessing nanoscale structural features and a substantial electrochemically active surface area have the potential to significantly enhance power characteristics and the cycle life. This might bring about substantial changes to existing energy storage models. The primary objective of this research is to summarize the latest advancements in utilizing nanomaterials for energy harvesting in various all-solid-state battery assemblies. This study examines the most complex solid-solid interfaces of all-solid-state batteries, as well as feasible methods for implementing nanomaterials in such interfaces. Currently, there is significant attention on the necessity to develop electrode-solid electrolyte interfaces that exhibit nanoscale particle articulation and other characteristics related to the behavior of lithium ions.

"Fast-Charging" Anode Materials for Lithium-Ion Batteries from Perspective of Ion Diffusion in Crystal Structure

"Fast-charging" lithium-ion batteries have gained a multitude of attention in recent years since they could be applied to energy storage areas like electric vehicles, grids, and subsea operations. Unfortunately, the excellent energy density could fail to sustain optimally while lithium-ion batteries are exposed to fast-charging conditions. In actuality, the crystal structure of electrode materials represents the critical factor for influencing the electrode performance. Accordingly, employing anode materials with low diffusion barrier could improve the "fast-charging" performance of the lithium-ion battery. In this Review, first, the "fast-charging" principle of lithium-ion battery and ion diffusion path in the crystal are briefly outlined. Next, the application prospects of "fast-charging" anode materials with various crystal structures are evaluated to search "fast-charging" anode materials with stable, safe, and long lifespan, solving the remaining challenges associated with high power and high safety. Finally, summarizing recent research advances for typical "fast-charging" anode materials, including preparation methods for advanced morphologies and the latest techniques for ameliorating performance. Furthermore, an outlook is given on the ongoing breakthroughs for "fast-charging" anode materials of lithium-ion batteries. Intercalated materials (niobium-based, carbon-based, titanium-based, vanadium-based) with favorable cycling stability are predominantly limited by undesired electronic conductivity and theoretical specific capacity. Accordingly, addressing the electrical conductivity of these materials constitutes an effective trend for realizing fast-charging. The conversion-type transition metal oxide and phosphorus-based materials with high theoretical specific capacity typically undergoes significant volume variation during charging and discharging. Consequently, alleviating the volume expansion could significantly fulfill the application of these materials in fast-charging batteries.

Nanostructured Design Cathode Materials for Magnesium-Ion Batteries

Energy is undeniably one of the most fundamental requirements of the current generation. Solar and wind energy are sustainable and renewable energy sources; however, their unpredictability points to the development of energy storage systems (ESSs). There has been a substantial increase in the use of batteries, particularly lithium-ion batteries (LIBs), as ESSs. However, low rate capability and degradation due to electric load in long-range electric vehicles are pushing LIBs to their limits. As alternative ESSs, magnesium-ion batteries (MIBs) possess promising properties and advantages. Cathode materials play a crucial role in MIBs. In this regard, a variety of cathode materials, including Mn-based, Se-based, vanadium- and vanadium oxide-based, S-based, and Mg2+-containing cathodes, have been investigated by experimental and theoretical techniques. Results reveal that the discharge capacity, capacity retention, and cycle life of cathode materials need improvement. Nevertheless, maintaining the long-term stability of the electrode-electrolyte interface during high-voltage operation continues to be a hurdle in the execution of MIBs, despite the continuous research in this field. The current Review mainly focuses on the most recent nanostructured-design cathode materials in an attempt to draw attention to MIBs and promote the investigation of suitable cathode materials for this promising energy storage device.

Metal-Organic Assembly Strategy for the Synthesis of Layered Metal Chalcogenide Anodes for Na+ /K+ -Ion Batteries

Layered transition metal chalcogenides (MX, M=Mo, W, Sn, V; X=S, Se, Te) have large ion transport channels and high specific capacity, making them promising for large-sized Na⁺ /K⁺ energy-storage technologies. Nevertheless, slow reaction kinetics and huge volume expansion will induce an undesirable electrochemical performance. Numerous efforts have been devoted to designing MX anodes and enhancing their electrochemical performance. Based on the metal-organic assembly strategy, nanostructural engineering, combination with carbon materials, and component regulation can be easily realized, which effectively boost the performance of MX anodes. In this Review, we present a comprehensive overview on the synthesis of MX nanostructure using the metal-organic assembly strategy, which can realize the design of MX nanostructures, based on self-sacrificial templates, host@guest tailored templates, post-modified layer and derivative templates. The preparation routes and structure evolution are mainly discussed. Then, Mo-, W-, Sn-, V-based chalcogenides used for Na⁺ /K⁺ energy storage are reviewed, and the relationship between the structure and the electrochemical performance, as well as the energy storage mechanism are emphasized. In addition, existing challenges and future perspectives are also presented.

Pressure Stabilized Lithium-Aluminum Compounds with Both Superconducting and Superionic Behaviors

Superconducting and superionic behaviors have physically intriguing dynamic properties of electrons and ions, respectively, both of which are conceptually important and have great potential for practical applications. Whether these two phenomena can appear in the same system is an interesting and important question. Here, using crystal structure predictions and first-principle calculations combined with machine learning, we identify several stable Li-Al compounds with electride behavior under high pressure, and we find that the electronic density of states of some of the compounds has characteristics of the two-dimensional electron gas. Among them, we estimate that Li_{6}Al at 150 GPa has a superconducting transition temperature of around 29 K and enters a superionic state at a high temperature and wide pressure range. The diffusion in Li_{6}Al is found to be affected by an electride and attributed to the atomic collective motion. Our results indicate that alkali metal alloys can be effective platforms to study the abundant physical properties and their manipulation with pressure and temperature.

Three-Dimensional Holey Graphene Enwrapped Li3 V2 (PO4 )3 /N-Doped Carbon Cathode for High-Rate and Long-Life Li-Ion Batteries

Monoclinic Li₃ V₂ (PO₄ )₃ is a promising cathode material for high-power Li-ion batteries. Herein, a three-dimensional holey graphene enwrapped Li₃ V₂ (PO₄ )₃ /N-doped carbon (LVPNCHG) nanocomposite has been successfully synthesized. The holes could be in-situ and directly introduced in graphene through H₂ O₂ chemical etching in the synthesis process, which could remarkably enhance the ion and electron transport and greatly improve the electrochemical performance of the LVPNCHG electrode: 78 mAh g^-1 at 150 C, 86.1 % capacity retention over 2000 cycles at 10 C, and 96 % capacity retention over 500 cycles at 1 C under -20 °C. Moreover, in-situ distribution of relaxation time analysis was used to study LVPNCHG cathode during charge/discharge at 3.0-4.8 V, combined with in-situ X-ray diffraction measurement, and the results showed that a two-phase reaction mechanism was involved during the insertion of Li⁺ in the discharge process. Further demonstration of graphite//LVPNCHG full cell indicated great potential of the as-synthesized materials for practical application.

Mo-Incorporated Magnetite Fe3 O4 Featuring Cationic Vacancies Enabling Fast Lithium Intercalation for Batteries

Transition metal oxides (TMOs) as high-capacity electrodes have several drawbacks owing to their inherent poor electronic conductivity and structural instability during the multi-electron conversion reaction process. In this study, the authors use an intrinsic high-valent cation substitution approach to stabilize cation-deficient magnetite (Fe₃ O₄ ) and overcome the abovementioned issues. Herein, 5 at% of Mo⁴⁺ -ions are incorporated into the spinel structure to substitute octahedral Fe³⁺ -ions, featuring ≈1.7 at% cationic vacancies in the octahedral sites. This defective Fe_2.93 ▫_0.017 Mo_0.053 O₄ electrode shows significant improvements in the mitigation of capacity fade and the promotion of rate performance as compared to the pristine Fe₃ O₄ . Furthermore, physical-electrochemical analyses and theoretical calculations are performed to investigate the underlying mechanisms. In Fe_2.93 ▫_0.017 Mo_0.053 O₄ , the cationic vacancies provide active sites for storing Li⁺ and vacancy-mediated Li⁺ migration paths with lower energy barriers. The enlarged lattice and improved electronic conductivity induced by larger doped-Mo⁴⁺ yield this defective oxide capable of fast lithium intercalation. This is confirmed by a combined characterization including electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), galvanostatic intermittent titration technique (GITT) and density functional theory (DFT) calculation. This study provides a valuable strategy of vacancy-mediated reaction to intrinsically modulate the defective structure in TMOs for high-performance lithium-ion batteries.

Construction of Low-Impedance and High-Passivated Interphase for Nickel-Rich Cathode by Low-Cost Boron-Containing Electrolyte Additive

The nickel-rich cathode LiNi_0.8 Co_0.1 Mn_0.1 O₂ (NCM811) possesses the advantages of high reversible specific capacity and low cost, thus regarded as a promising cathode material for lithium-ion batteries (LIBs). However, the capacity of the NCM811 decays rapidly at high voltage due to the extremely unstable electrode/electrolyte interphase. The discharge capability at low temperature is also impaired because of the increasing interfacial impedance. Herein, a low-cost film-forming electrolyte additive with multi-function, phenylboronic acid (PBA), was employed to modify the interphasial properties of the NCM811 cathode. Theoretical calculation and experimental results showed that PBA constructed a highly conductive and steady cathode electrolyte interphase (CEI) film through preferential oxidation decomposition, which greatly improved the interfacial properties of the NCM811 cathode at room (25 °C) and low temperature (-10 °C). Specifically, the capacity retention of NCM811/Li cell was increased from 68 % to 87 % after 200 cycles with PBA additive. Moreover, the NCM811/Li cell with PBA additive delivered higher discharge capacity under -10 °C at 0.5 C (173.7 mAh g^-1 vs. 111.1 mAh g^-1 ). Based on the improvement of NCM811 interphasial properties by additive PBA, the capacity retention of NCM811/graphite full-cell was enhanced from 49 % to 65 % after 200 cycles.

A Facile Microwave Hydrothermal Method for Fabricating SnO2@C/Graphene Composite With Enhanced Lithium Ion Storage Properties

SnO₂@C/graphene ternary composite material has been prepared via a double-layer modified strategy of carbon layer and graphene sheets. The size, dispersity, and coating layer of SnO₂@C are uniform. The SnO₂@C/graphene has a typical porous structure. The discharge and charge capacities of the initial cycle for SnO₂@C/graphene are 2,210 mAh g⁻¹ and 1,285 mAh g⁻¹, respectively, at a current density of 1,000 mA g⁻¹. The Coulombic efficiency is 58.60%. The reversible specific capacity of the SnO₂@C/graphene anode is 955 mAh g⁻¹ after 300 cycles. The average reversible specific capacity still maintains 572 mAh g⁻¹ even at the high current density of 5 A g⁻¹. In addition, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are performed to further investigate the prepared SnO₂@C/graphene composite material by a microwave hydrothermal method. As a result, SnO₂@C/graphene has demonstrated a better electrochemical performance.

Photoactive nanomaterials enabled integrated photo-rechargeable batteries

The research interest in energy storage systems (e.g. batteries and capacitors) has been increasing over the last years. The rising need for electricity storage and overcoming the intermittent nature of renewable energy sources have been potent drivers of this increase. Solar energy is the most abundant renewable energy source. Thus, the combination of photovoltaic devices with energy storing systems has been pursued as a novel approach in applications such as electric vehicles and smart grids. Among all the possible configurations, the "direct" incorporation of photoactive materials in the storing devices is most attractive because it will enhance efficiency and reduce volume/weight compared to conventional systems comprised two individual devices. By generating and storing electricity in a singular device, integrated photo-rechargeable batteries offer a promising solution by directly storing electricity generated by sunlight during the day and reversibly releasing it at night time. They hold a sizable potential for future commercialization. This review highlights cutting-edge photoactive nanomaterials serving as photoelectrodes in integrated photobatteries. The importance and influence of their structure and morphology and relevant photocatalytic mechanisms will be focal points, being strong influencers of device performance. Different architecture designs and working principles are also included. Finally, challenges and limitations are discussed with the aim of providing an outlook for further improving the performance of integrated devices. We hope this up-to-date, in-depth review will act as a guide and attract more researchers to this new, challenging field, which has a bright application prospect.

Disulfide bond-embedded polyurethane solid polymer electrolytes with self-healing and shape-memory performance

In this work, solid-state polymer electrolytes with both self-healing and shape-memory properties (SSSPEs) are designed and fabricated based on disulfide bond-containing polyurethane and poly(ethylene oxide) (PEO) segments.

Aligned Carbon-Based Electrodes for Fast-Charging Batteries: A Review

Fast-charging batteries have attracted great attention, and are anticipated to charge electrical vehicles and consumer electronics to full-capacity in several minutes. However, commercial electrode materials in batteries generally have a limited rate performance and are difficult to be used in fast-charging batteries. Designing electrodes with an aligned structure is an effective way to shorten the ion transport path and improve the rate performance of a battery. The excellent electronic conductivity of carbon-based electrodes is another key factor for increasing the rate capability of rechargeable batteries. Therefore, aligned carbon-based electrodes (ACBEs) can significantly improve the power density by combining the advantages of an aligned structure and carbon-based materials. In this review, the mechanism, advantages, and challenges of ACBEs for fast-charging batteries are evaluated, and then the design and preparation methods of ACBEs based on their different dimensions are summarized, and their applications in different batteries are illustrated. Finally, the future development of ACBEs for fast-charging batteries is considered.