Reduction-Tolerance Electrolyte Design for High-Energy Lithium Batteries.

Lithium batteries employing Li or silicon (Si) anodes hold promise for the next-generation energy storage systems. However, their cycling behavior encounters rapid capacity degradation due to the vulnerability of solid electrolyte interphases (SEIs). Though anion-derived SEIs mitigate this degradation, the unavoidable reduction of solvents introduces heterogeneity to SEIs, leading to fractures during cycling.

Unraveling the Solvent Effect on Solid-Electrolyte Interphase Formation for Sodium Metal Batteries.

Ether-based electrolytes are considered as an ideal electrolyte system for sodium metal batteries (SMBs) due to their superior compatibility with the sodium metal anode (SMA). However, the selection principle of ether solvents and the impact on solid electrolyte interphase formation are still unclear. Herein, we systematically compare the chain ether-based electrolyte and understand the relationship between the solvation structure and the interphasial properties.

Interphasial Pre-lithiation and Reinforcement of Micro-Si Anode through Fluorine-free Electrolytes.

Micro-sized silicon (mSi) anodes offer advantages in cost and tap density over nanosized counterparts. However, its practical application still suffers from poor cyclability and low initial and later-cycle coulombic efficiency (CE), caused by the unstable solid electrolyte interphase (SEI) and irreversible lithiation of the surface oxide layer. Herein, a bifunctional fluorine (F)-free electrolyte was designed for the mSi anode to stabilize the interphase and improve the CE.

Interphase Engineering Enhanced Electro-chemical Stability of Prelithiated Anode.

Prelithiation is an essential technology to compensate for the initial lithium loss of lithium-ion batteries due to the formation of solid electrolyte interphase (SEI) and irreversible structure change. However, the prelithiated materials/electrodes become more reactive with air and electrolyte resulting in unwanted side reactions and contaminations, which makes it difficult for the practical application of prelithiation technology. To address this problem, herein, interphase engineering through a simple solution treatment after chemical prelithiation is proposed to protect the prelithiated electrode.

Temperature-dependent interphase formation and Li transport in lithium metal batteries.

High-performance Li-ion/metal batteries working at a low temperature (i.e., <-20 °C) are desired but hindered by the sluggish kinetics associated with Li transport and charge transfer.

Multifunctional solvent molecule design enables high-voltage Li-ion batteries.

Elevating the charging cut-off voltage is one of the efficient approaches to boost the energy density of Li-ion batteries (LIBs). However, this method is limited by the occurrence of severe parasitic reactions at the electrolyte/electrode interfaces. Herein, to address this issue, we design a non-flammable fluorinated sulfonate electrolyte by multifunctional solvent molecule design, which enables the formation of an inorganic-rich cathode electrolyte interphase (CEI) on high-voltage cathodes and a hybrid organic/inorganic solid electrolyte interphase (SEI) on the graphite anode.

In Situ Detecting Thermal Stability of Solid Electrolyte Interphase (SEI).

Solid electrolyte interphase (SEI) plays an important role in regulating the interfacial ion transfer and safety of Lithium-ion batteries (LIBs). It is unstable and readily decomposed releasing much heat and gases and thus triggering thermal runaway. Herein, in situ heating X-ray photoelectron spectroscopy is applied to uncover the inherent thermal decomposition process of the SEI.

Tailoring polymer electrolyte ionic conductivity for production of low- temperature operating quasi-all-solid-state lithium metal batteries.

The stable operation of lithium-based batteries at low temperatures is critical for applications in cold climates. However, low-temperature operations are plagued by insufficient dynamics in the bulk of the electrolyte and at electrode|electrolyte interfaces. Here, we report a quasi-solid-state polymer electrolyte with an ionic conductivity of 2.

Conformal Coating of a High-Voltage Spinel to Stabilize LiCoO at 4.6 V.

The ever-growing demand for portable electronic devices has put forward higher requirements on the energy density of layered LiCoO (LCO). The unstable surface structure and side reactions with electrolytes at high voltages (>4.5 V) however hinder its practical applications.

Efficient Charge Transfer and Effective Active Sites in Lead-Free Halide Double Perovskite S-Scheme Heterojunctions for Photocatalytic H Evolution.

The practical application of lead-free double perovskite Cs AgBiBr in photocatalytic H evolution is still restricted due to the low activity and poor stability. The rational design of lead-free halide double perovskites heterojunctions with efficient charge transfer and effective active sites is a potential route to achieve the ideal prospect. Herein, in this work an S-scheme heterojunction of Cs AgBiBr with enriched Br-vacancies and WO nanorods (V -Cs AgBiBr /WO ) obtaining excellent visible-light responsive photocatalytic H evolution performance and durable stability is reported.

Solvation and Interfacial Engineering Enable -40 °C Operation of Graphite/NCM Batteries at Energy Density over 270 Wh kg.

Li-ion batteries (LIBs) that can operate under low temperature (LT) conditions are essential for applications in orbital missions, subsea areas, and electric vehicles. Unfortunately, severe capacity loss is witnessed due to tremendous kinetic barriers that emerge at LT. Herein, to surmount such kinetic limitations, a low dielectric environment is tamed throughout the bulk electrolyte, which efficaciously brought the Li desolvation energy down to 30.

Chemically Induced Activity Recovery of Isolated Lithium in Anode-free Lithium Metal Batteries.

The anode-free lithium metal battery is considered to be an excellent candidate for the new generation energy storage system because of its higher energy density and safety than the traditional lithium metal battery. However, the continuous generation of SEI or isolated Li hinders its practical application. In general, the isolated Li is considered electrochemically inactive because it loses electrical connection with the current collector.

Tackling realistic Li flux for high-energy lithium metal batteries.

Electrolyte engineering advances Li metal batteries (LMBs) with high Coulombic efficiency (CE) by constructing LiF-rich solid electrolyte interphase (SEI). However, the low conductivity of LiF disturbs Li diffusion across SEI, thus inducing Li transfer-driven dendritic deposition. In this work, we establish a mechanistic model to decipher how the SEI affects Li plating in high-fluorine electrolytes.

50C Fast-Charge Li-Ion Batteries using a Graphite Anode.

Li-ion batteries have made inroads into the electric vehicle market with high energy densities, yet they still suffer from slow kinetics limited by the graphite anode. Here, electrolytes enabling extreme fast charging (XFC) of a microsized graphite anode without Li plating are designed. Comprehensive characterization and simulations on the diffusion of Li in the bulk electrolyte, charge-transfer process, and the solid electrolyte interphase (SEI) demonstrate that high ionic conductivity, low desolvation energy of Li , and protective SEI are essential for XFC.

Platinum atomic clusters embedded in polyoxometalates-carbon black as an efficient and durable catalyst for hydrogen evolution reaction.

Platinum-based catalysts are regarded as the Holy Grail of hydrogen evolution reaction (HER). As a benchmark catalyst for HER, the commercial Pt/C catalyst has low Pt utilization efficiency and high cost, which hinders its commercialization. Atomic clusters-based catalysts show high efficiency of atom utilization and high performance toward electrocatalysis.

Deciphering the Role of Fluoroethylene Carbonate towards Highly Reversible Sodium Metal Anodes.

Sodium metal anodes (SMAs) suffer from extremely low reversibility (<20%) in carbonate-based electrolytes-this piece of knowledge gained from previous studies has ruled out the application of carbonate solvents for sodium metal batteries. Here, we overturn this conclusion by incorporating fluoroethylene carbonate (FEC) as cosolvent that renders a Na plating/stripping efficiency of >95% with conventional NaPF salt at a regular concentration (1.0 M).

Cryo-EM for battery materials and interfaces: Workflow, achievements, and perspectives.

The emerging cryogenic electron microscopy (cryo-EM) has demonstrated its power and essential role in probing the beam-sensitive battery materials and delivering new insights. With the increasing interest in cryo-EM for battery materials and interfaces, herein we provide the strategies of obtaining fresh and native structural information with minimal artifacts, including sample preparation, transferring, imaging, and data interpretation. We summarize the recent achievements enabled by cryo-EM and point out some unsolved/potential questions in terms of the bulk materials, solid-solid interface, and solid-liquid interfaces of batteries.

Anionic Effect on Enhancing the Stability of a Solid Electrolyte Interphase Film for Lithium Deposition on Graphite.

Graphitic carbons and their lithium composites have been utilized as lithium deposition substrates to address issues such as the huge volume variation and dendritic growth of lithium. However, new problems have appeared, including the severe exfoliation of the graphite particles and the instability of the solid electrolyte interphase (SEI) film when metallic lithium is plated on the graphite. Herein, we enhance the stability of the SEI film on the graphite substrate for lithium deposition in an electrolyte of lithium bis(fluorosulfonyl)imide (LiFSI) dissolved in the carbonate solvent, thereby improving the lithium plating/stripping cycle on it.