Delineating the Triphasic Side Reaction Products in High-Energy Density Lithium-Ion Batteries.

Unwanted cathode-electrolyte side reactions remain a major challenge to the stability of lithium-ion batteries, especially at high temperatures. This study presents a quantitative analysis on gaseous, soluble, and solid byproducts generated by reactions between LiNiO and carbonate electrolytes. Online electrochemical mass spectrometry (OEMS) outgassing profiles reveal the emergence of a pre-plateau region as temperature increases, characterized by two small plateaus at 3.

Locally Confined Polysulfide-Reactive Electrolytes for Shuttle-Free Sodium-Sulfur Batteries.

Sodium-sulfur batteries promise high-energy-density and sustainable electrochemical energy storage but suffer from uncontrolled polysulfide dissolution and high sodium reactivity. These challenges fundamentally originate from poor electrolyte-electrode compatibility. Current electrolyte research inadequately addresses the trade-off between minimal polysulfide solvation and stabilizing sodium interfaces.

Inner-Outer Sheath Synergistic Shielding of Polysulfides in Asymmetric Solvent-Based Electrolytes for Stable Sodium-Sulfur Batteries.

Room-temperature sodium-sulfur (RT Na-S) batteries are garnering interest owing to their high theoretical energy density and low cost. However, the notorious shuttle behavior of sodium polysulfides (NaPS) and uncontrollable dendrite growth lead to the poor cycle stability of RT Na-S cells. In this work, we report the use of 1,2-dimethoxypropane (DMP) and 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether (TFTFE) as inner solvent and outer diluent, respectively, in a localized high-concentration electrolyte system.

Enhanced Electrochemical Stability in All-Solid-State Lithium-Sulfur Batteries with Lithium Argyrodite Electrolyte.

Lithium argyrodite electrolytes with halide dopings (LiPSX, X = Cl, Br, I) are a group of sulfide solid electrolyte materials (SSEs) widely adopted in all-solid-state lithium-sulfur batteries (ASSLSBs) for their ease of processing and low material costs. Specifically, the Cl-doped lithium argyrodite electrolytes, with the highest ionic conductivities among the halide-doped lithium argyrodite electrolytes, are extensively studied in the literature. However, their narrow electrochemical stability window limits the performance of ASSLSBs due to the inevitable electrolyte decomposition within the operating voltage window.

Macromolecule-Enriched Solvation Enabling High-Voltage Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) are emerging as a viable alternative for sustainable and cost-effective energy storage, yet their energy density is curtailed by relatively low voltage outputs (< 4 V) due to the lack of high-voltage electrolytes. Here, for the first time, we describe a high-voltage Na electrolyte featuring a macromolecule-enriched solvation architecture. The vulnerable small molecules in the Na solvation shell are replaced by macro polyamide (PA) molecules with high thermodynamic resilience, ensuring a wide electrochemical stability window for the electrolytes with suppressed oxidative/reductive decomposition.

A Perspective on Pathways Toward Commercial Sodium-Ion Batteries.

Lithium-ion batteries (LIBs) have been widely adopted in the automotive industry, with an annual global production exceeding 1000 GWh. Despite their success, the escalating demand for LIBs has created concerns on supply chain issues related to key elements, such as lithium, cobalt, and nickel. Sodium-ion batteries (SIBs) are emerging as a promising alternative due to the high abundance and low cost of sodium and other raw materials.

Redox-Active Halide Catholytes for Enhanced Energy Density in Solid-State Sodium Batteries.

Sodium-based all-solid-state batteries (ASSBs) are a promising technology for grid-scale energy storage applications due to their theoretically low cost and high energy density. However, state-of-the-art ASSB cathodes are often in the form of heterogeneous composites with 20-40% inactive solid catholyte, which undermines the energy density benefits of the solid-state format. Furthermore, solid catholytes are often comprised of cost-prohibitive, rare metals.

Deciphering the Impact of Polysulfide Solvation Structure on Electrical Double Layer Chemistry in Sodium-Sulfur Batteries.

Room-temperature sodium-sulfur (RT Na-S) batteries are garnering attention for large-scale energy storage. However, their practical application is hindered by challenges, such as the shuttle effect of sodium polysulfides (NaPS) and dendrite growth. The high solubility of NaPS in the electrolyte is particularly problematic.

Multi-dimensional, Multi-scale Analysis of Interphase Chemistry for Enhanced Fast-Charging of Lithium-Ion Batteries with Ion Mass Spectrometry.

Understanding the fundamental properties of electrode-electrolyte interphases (EEIs) is essential for designing electrolytes that support stable operation under high charging rates. In this study, we benchmark our fast-charging electrolyte (FCE) against the commercial LP57 electrolyte to identify the EEI characteristics that enhance fast-charging performance. By utilizing the latest advances in time-of-flight secondary ion mass spectrometry (TOF-SIMS) and focused-ion beam (FIB) techniques, we reveal the complex chemical architecture of the cathode-electrolyte interphase (CEI).

Long-life graphite-lithium sulfide full cells enabled through a solvent Co-intercalation-free electrolyte design.

Graphite (Gr) is the predominant anode material for current lithium-ion technologies. The Gr anode could offer a practical pathway for the development of lithium-sulfur (Li-S) batteries due to its superior stability and safety compared to Li-metal. However, Gr anodes are not compatible with the conventional dilute ether-based electrolytes typically used in Li-S systems.

A New Class of Oxyhalide Solid Electrolytes NaNbClO for Solid-state Sodium Batteries.

Sodium-based batteries are gaining momentum due to the abundance and lower cost of sodium compared to lithium. Solid-state sodium batteries can also provide further safety advantages. However, sodium-based solid-state electrolytes (SSEs) that meet all the rigorous requirements, such as high ionic conductivity, oxidative stability with the cathode, and ease of processability, are lacking.

Unveiling the Influence of Water Molecules on the Structural Dynamics of Prussian Blue Analogues.

3D-framework Prussian blue analogues (PBAs) are appealing as a cost-effective, sustainable cathodes for Na-ion batteries. However, the aqueous-based synthesis of PBAs inherently introduces three different forms of water molecules (surface, interstitial and crystal) into the structure. Removal of water molecules causes phase transformation from monoclinic (M) to rhombohedral (R).

Effects of Coprecipitation Conditions on the Electrochemical Properties of Cobalt-Free LiNiMnAlO Cathodes.

Commercializing high-nickel, cobalt-free cathodes, such as LiNiMnAlO (NMA-90), hinges on effectively incorporating Al during the hydroxide coprecipitation reaction. However, Al coprecipitation is nontrivial as Al possesses unique precipitation properties compared to Ni and Mn, which impact the final precursor morphology and consequently the cathode properties. In this study, the nuance of Al coprecipitation and its influence on the cycling stability of NMA with increasing Al content is elucidated.

Enabling Stable Operation of Lithium-Ion Batteries under Fast-Operating Conditions by Tuning the Electrolyte Chemistry.

Inferior fast-charging and low-temperature performances remain a hurdle for lithium-ion batteries. Overcoming this hurdle is extremely challenging primarily due to the low conductivity of commercial ethylene carbonate (EC)-based electrolytes and the formation of undesirable solid electrolyte interphases with poor Li-ion diffusion kinetics. Here, a series of EC-free fast-charging electrolytes (FCEs) by incorporating a fluorinated ester, methyl trifluoroacetate (MTFA), as a special cosolvent into a practically viable LiPF-dimethyl carbonate-fluoroethylene carbonate system, is reported.

Enhancing the Mn Redox Kinetics of LiMnFePO Cathodes Through a Synergistic Co-Doping with Niobium and Magnesium for Lithium-Ion Batteries.

The concerns on the cost of lithium-ion batteries have created enormous interest on LiFePO (LFP) and LiMnFePO (LMFP) cathodes However, the inclusion of Mn into the olivine structure causes a non-uniform atomic distribution of Fe and Mn, resulting in a lowering of reversible capacity and hindering their practical application. Herein, a co-doping of LMFP with Nb and Mg is presented through a co-precipitation reaction, followed by a spray-drying process and calcination. It is found that LiNbO formed with the aliovalent Nb doping resides mainly on the surface, while the isovalent Mg doping occurs into the bulk of the particle.

Design of Localized High Concentration Electrolytes for Fast-Charging Lithium-Ion Batteries.

Localized high-concentration electrolytes (LHCEs) have emerged as a promising class of electrolytes to improve the cycle life and energy density of lithium-ion batteries (LIBs). While their application in batteries with lithium-metal anodes is extensively investigated, their behavior in systems with graphite anodes has received less research attention. Herein, the behaviors of four electrolytes in Graphite | LiNiO cells are compared.

Impact of Electrolyte on Direct-Contact Prelithiation of Silicon-Graphite Anodes in Lithium-Ion Cells with High-Nickel Cathodes.

Silicon-based anodes offer high specific capacities to enhance the energy density of lithium-ion batteries, but are severely hindered by the immense volume expansion and subsequent breakage of the solid-electrolyte-interphase (SEI) during cycling. Herein, we utilize an effective strategy, known as direct-contact prelithiation, to mitigate the challenges associated with expansion and surface instability in SiO/graphite (SG) anodes. It involves introducing lithium into the anode via physical contact with lithium metal and electrolyte before cycling.

Regulating Anode-Electrolyte Interphasial Reactions by Zwitterionic Binder Chemistry in Lithium-Ion Batteries with High-Nickel Layered Oxide Cathodes and Silicon-Graphite Anodes.

The practical application of silicon (Si)-based anodes faces challenges due to severe structural and interphasial degradations. These challenges are exacerbated in lithium-ion batteries (LIBs) employing Si-based anodes with high-nickel layered oxide cathodes, as significant transition-metal crossover catalyzes serious parasitic side reactions, leading to faster cell failure. While enhancing the mechanical properties of polymer binders has been acknowledged as an effective means of improving solid-electrolyte interphase (SEI) stability on Si-based anodes, an in-depth understanding of how the binder chemistry influences the SEI is lacking.

Anode-Free Lithium-Sulfur Batteries with a Rare-Earth Triflate as a Dual-Function Electrolyte Additive.

Anode-free lithium-sulfur batteries feature a cell design with a fully lithiated cathode and a bare current collector as an anode to control the total amount of lithium in the cell. The lithium stripping and deposition are key factors in designing an anode-free full cell to realize a practical cell configuration. To realize effective anode protection and achieve a good performance of the anode-free full cell, manipulation of the electrolyte chemistry toward the modification of the solid-electrolyte interphase on the anode is considered a feasible approach.

Formation and Detriments of Residual Alkaline Compounds on High-Nickel Layered Oxide Cathodes.

High-nickel layered oxides LiNiMO (x ≥ 0.9) have emerged as promising cathode materials for automotive batteries due to their high energy density and lower cost. However, the formation and accumulation of surface alkaline compounds during storage hinder their mass production and commercialization.

A Class of Sodium Transition-Metal Sulfide Cathodes With Anion Redox.

Sodium-ion batteries (SIBs) are entering commercial relevance as a sustainable and low-cost alternative to lithium-ion batteries. Improving the energy density of SIBs is critical to enable their widespread adoption. Here, a new class of cathode materials NaMS (M = Co, Mn, Fe, and Zn) that exhibit high charge-storage capacity is reported.

Electrolyte-Enabled High-Voltage Operation of a Low-Nickel, Low-Cobalt Layered Oxide Cathode for High Energy Density Lithium-Ion Batteries.

The lithium-ion battery industry acknowledges the need to reduce expensive metals, such as cobalt and nickel, due to supply chain challenges. However, doing so can drastically reduce the overall battery energy density, attenuating the driving range for electric vehicles. Cycling to higher voltages can increase the capacity and energy density but will consequently exacerbate cell degradation due to the instability at high voltages.

Structure and Properties of NaS-SiS-PS-NaPO Glassy Solid Electrolytes.

In the development of sodium all-solid-state batteries (ASSBs), research efforts have focused on synthesizing highly conducting and electrochemically stable solid-state electrolytes. Glassy solid electrolytes (GSEs) have been considered very promising due to their tunable chemistry and resistance to dendrite growth. For these reasons, we focus here on the atomic-level structures and properties of GSEs in the compositional series (0.

Mitigating Sodium Ordering for Enhanced Solid Solution Behavior in Layered NaNiO Cathodes.

The O-type layered nickel oxides suffer from undesired cooperative Jahn-Teller distortion stemming from Ni ions and undergo multiple biphasic structural transformations during the insertion/extraction of large Na ions, posing a significant challenge to stabilize the structural integrity. We present here a systematic investigation of the impact of substituting 5 % divalent (Mg) or trivalent (Al or Co) ions for Ni to alleviate Naion ordering and perturb the Jahn-Teller effect to enhance structural stability. We gauge a fundamental understanding of the Mg-O and Na-O or Mg-O-Na bonding interactions, noting that the ionicity of the Mg-O bond deshields the electronic cloud of oxygen from Na ions.

Rechargeable Metal-Sulfur Batteries: Key Materials to Mechanisms.

Rechargeable metal-sulfur batteries are considered promising candidates for energy storage due to their high energy density along with high natural abundance and low cost of raw materials. However, they could not yet be practically implemented due to several key challenges: (i) poor conductivity of sulfur and the discharge product metal sulfide, causing sluggish redox kinetics, (ii) polysulfide shuttling, and (iii) parasitic side reactions between the electrolyte and the metal anode. To overcome these obstacles, numerous strategies have been explored, including modifications to the cathode, anode, electrolyte, and binder.