Sequencing-Dependent Impact of Carbon Coating on Microstructure Evolution and Electrochemical Performance of Pre-lithiated SiO Anodes: Enhanced Efficiency and Stability via Pre-Coating Strategy.

Silicon monoxide (SiO) has attracted considerable interest as anode material for lithium-ion batteries (LIBs). However, their poor initial Coulombic efficiency (ICE) and conductivity limit large-scale applications. Prelithiation and carbon-coating are common and effective strategies in industry for enhancing the electrochemical performance of SiO. However, the involved heat-treatment processes inevitably lead to coarsening of active silicon phases, posing a significant challenge in industrial applications. Herein, the differences in microstructures and electrochemical performances between prelithiated SiO with a pre-coated carbon layer (SiO@C@PLi) and SiO subjected to carbon-coating after prelithiation (SiO@PLi@C) are investigated. A preliminary carbon layer on the surface of SiO before prelithiation is found that can suppress active Si phase coarsening effectively and regulate the post-prelithiation phase content. The strategic optimization of the sequence where prelithiation and carbon-coating processes of SiO exert a critical influence on its regulation of microstructure and electrochemical performances. As a result, SiO@C@PLi exhibits a higher ICE of 88.0%, better cycling performance and lower electrode expansion than SiO@PLi@C. The pouch-type full-cell tests demonstrate that SiO@C@PLi/Graphite||NCM811 delivers a superior capacity retention of 91% after 500 cycles. This work provides invaluable insights into industrial productions of SiO anodes through optimizing the microstructure of SiO in prelithiation and carbon-coating processes.

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 SiOx/graphite (SG) anodes. It involves introducing lithium into the anode via physical contact with lithium metal and electrolyte before cycling. Prelithiation of SG anodes with an advanced localized high-concentration electrolyte is shown to develop a mechanically robust artificial SEI that tolerates better the electrode volume expansion. The modified SG anode paired with the high-Ni cathode LiNi0.90Mn0.05Co0.05O2 delivers a high initial capacity of 191 mA h g-1 with 80% capacity retention over 150 cycles, compared to 46% retention with a conventional electrolyte. The bolstered SEI layer with reduced surface reactivity is due to the reduced electrolyte consumption and regulated SEI formation during cycling. Furthermore, the advanced electrolyte and fortified SG anode help reduce cathode degradation, transition-metal dissolution, and loss of active lithium. This study highlights viable prelithiation strategies to stabilize Si-based anodes for high-energy-density batteries through electrolyte design.

Mechanically Robust Current Collector with Gradient Lithiophilicity Induced by Spontaneous Lithium Ion Diffusion for Stable Lean-Lithium Metal Batteries.

Lean-lithium metal batteries represent an advanced version of the anode-free lithium metal batteries, which can ensure high energy density and cycling stability while addressing the safety concerns and the loss of energy density caused by excessive lithium metal. Herein, a mechanically robust carbon nanotube framework current collector with gradient lithiophilicity is constructed for a lean-lithium metal battery. Using the physical vapor deposition method, precise prelithiation of a carbon nanotube framework is achieved, eliminating its irreversible capacity, retaining the porous structure in the framework, and inducing the gradient lithiophilicity formation due to spontaneous lithium ion diffusion. The lithiophilic gradient and three-dimensional porous structure are characterized by time-of-flight secondary ion mass spectrometry (TOF-SIMS), scanning transmission electron microscopy (STEM), and corresponding electron energy loss spectroscopy (EELS), which enables the preferential deposition of lithium ions at the bottom of the carbon nanotube framework, thereby avoiding lithium losses associated with dead lithium. As a result, in the LiFePO4 full cell with an ultralow N/P ratio of 0.15, the initial Coulombic efficiency increases from 77.75 to 95.07%. Collaborating synergistically with the ultrathin (1.5 µm) lithium metal, serving as a gradual lithium supplement, the full cell with an N/P ratio of 1.43 demonstrates an 86% capacity retention after 500 cycles at 1C, far surpassing the copper-based counterparts (0.9%).

Favored Amorphous LixSi Process with Restrained Volume Change Enabling Long Cycling Quasi-solid-state SiOx anode.

Silicon-based anodes are becoming promising materials due to their high specific capacity. However, the intrinsically large volume change brought about by the alloying reaction results in the crushing of the active particles and destruction of the electrode structure, which severely limits its practical application. Various structured and modified silica-based anodes exhibit improved cycling stability and the demonstrated ability to mitigate their volume changes through interfacial and binder strategies. However, the issue of large volume changes in silicon-based anodes remains. Herein, we report a gel polymer electrolyte (GPE) prepared through an in situ thermal polymerization process that is suitable for SiOx anode materials and achieving long-term cycling stability. GPE-based cells essentially mitigate the volume change of SiOx anodes by guiding the unique lithiation/delithiation mechanism that tends to favor the formation and delithiation of amorphous-LixSi (a-LixSi) with smaller volume change, thereby mitigating electrode damage and cracking, and achieving the significant improvement in cycling performance. The prepared GPE-SiOx cells retained 693.80 mAh g-1 reversible capacity after 450 cycles at 500 mA g-1. In addition, the prelithiation process was incorporated to mitigate capacity fluctuations and improve the Initial Coulombic Efficiency (ICE), and a reversible capacity of 641.90 mAh g-1 was retained after 480 cycles.

Electrocatalytic Decomposition of Lithium Oxalate-Based Composite Microspheres as a Prelithiation Additive in Lithium-Ion Batteries.

In conventional lithium-ion batteries (LIBs), the active lithium from the lithium-containing cathode is consumed by the formation of a solid electrolyte interface (SEI) at the anode during the first charge, resulting in irreversible capacity loss. Prelithiation additives can provide additional active lithium to effectively compensate for lithium loss. Lithium oxalate is regarded as a promising ideal cathode prelithiation agent; however, the electrochemical decomposition of lithium oxalate is challenging. In this work, a hollow and porous composite microsphere was prepared using a mixture of lithium oxalate, Ketjen Black and transition metal oxide catalyst, and the formulation was optimized. Owing to the compositional and structural merits, the decomposition voltage of lithium oxalate in the microsphere was reduced to 3.93 V; when being used as an additive, there is no noticeable side effect on the performance of the cathode material. With 4.2% of such an additive, the first discharge capacity of the LiFePO4‖graphite full cell increases from 139.1 to 151.9 mAh g-1, and the coulombic efficiency increases from 88.1% to 96.3%; it also facilitates the formation of a superior SEI, leading to enhanced cycling stability. This work provides an optimized formula for developing an efficient prelithiation agent for LIBs.

In Situ Construction of Specific SEI Layer Affords Effective Prelithiation.

Silicon-based anodes have been attracting attention due to their high theoretical specific capacity, but their low initial Coulombic efficiency (ICE) seriously hinders their commercial application. Direct contact prelithiation is considered to be one of the effective means of solving this problem. By means of prelithiation, a specific solid electrolyte interphase (SEI) was constructed, which inhibited the volume expansion of the SiO/C composite anode during prelithiation and reduced the local current generated when the lithium source was in contact with the anode. On the one hand, it can reduce the side reactions derived from the decomposition of electrolytes in the prelithiation process, and on the other hand, it can slow down the prelithiation process and inhibit the volume expansion of the SiO/C composite anode in the prelithiation process. The results of XPS, TOF-SIMS, and other tests show that the use of an electrolyte whose main component is LiTFSI can construct SEI film whose main component is LiF, which to a certain extent can slow down the rate of prelithiation, reduce the local current generated when the lithium source is in contact with the negative electrode, minimize the occurrence of side reactions, and inhibit the volume expansion of the negative electrode material. The full battery assembled with NCM111 positive electrode still exhibits 83.5% capacity retention after 500 cycles at 1 C current density. These studies provide some ideas to enhance the performance of silicon-based materials.

Chemical Prelithiated 3D Lithiophilic/-Phobic Interlayer Enables Long-Term Li Plating/Stripping.

The up-to-date lifespan of zero-excess lithium (Li) metal batteries is limited to a few dozen cycles due to irreversible Li-ion loss caused by interfacial reactions during cycling. Herein, a chemical prelithiated composite interlayer, made of lithiophilic silver (Ag) and lithiophobic copper (Cu) in a 3D porous carbon fiber matrix, is applied on a planar Cu current collector to regulate Li plating and stripping and prevent undesired reactions. The Li-rich surface coating of lithium oxide (Li2O), lithium carboxylate (RCO2Li), lithium carbonates (ROCO2Li), and lithium hydride (LiH) is formed by soaking and directly heating the interlayer in n-butyllithium hexane solution. Although only a thin coating of ∼10 nm is created, it effectively regulates the ionic and electronic conductivity of the interlayer via these surface compounds and reduces defect sites by reactions of n-butyllithium with heteroatoms in the carbon fibers during formation. The spontaneously formed lithiophilic-lithiophobic gradient across individual carbon fiber provides homogeneous Li-ion deposition, preventing concentrated Li deposition. The porous structure of the composite interlayer eliminates the built-in stress upon Li deposition, and the anisotropically distributed carbon fibers enable uniform charge compensation. These features synergistically minimize the side reactions and compensate for Li-ion loss while cycling. The prepared zero-excess Li metal batteries could be cycled 300 times at 1.17 C with negligible capacity fading.

Approaching Sustainable Lithium-Ion Batteries through Voltage-Responsive Smart Prelithiation Separator with Surface-Engineered Sacrificial Lithium Agents.

The surge in lithium-ion batteries has heightened concerns regarding metal resource depletion and the environmental impact of spent batteries. Battery recycling has become paramount globally, but conventional techniques, while effective at extracting transition metals like cobalt and nickel from cathodes, often overlook widely used spent LiFePO4 due to its abundant and low-cost iron content. Direct regeneration, a promising approach for restoring deteriorated cathodes, is hindered by practicality and cost issues despite successful methods like solid-state sintering. Hence, a smart prelithiation separator based on surface-engineered sacrificial lithium agents is proposed. Benefiting from the synergistic anionic and cationic redox, the prelithiation separator can intelligently release or intake active lithium via voltage regulation. The staged lithium replenishment strategy was implemented, successfully restoring spent LiFePO4's capacity to 163.7 mAh g-1 and a doubled life. Simultaneously, the separator can absorb excess active lithium up to approximately 600 mAh g-1 below 2.5 V to prevent over-lithiation of the cathode This innovative, straightforward, and cost-effective strategy paves the way for the direct regeneration of spent batteries, expanding the possibilities in the realm of lithium-ion battery recycling.

Dual-Carbon Phase-Encapsulated Prelithiated SiOx Microrod Anode for Lithium-Ion Batteries.

Among silicon-based anode family for Li-ion battery technology, SiOx, a nonstoichiometric silicon suboxide holds the potential for significant near-term commercial impact. In this context, this study mainly focuses on demonstrating an innovative SiOx@C anode design that adopts a pre-lithiation strategy based on in situ pyrolysis of Li-salt of silsesquioxane trisilanolate without the need for lithium metal or active lithium compounds and creates dual carbon encapsulation of SiOC nanodomains by simply one-step thermal treatment. This ingenious design ensures the pre-lithiation process and pre-lithiation material with high-environmental stability. Moreover, phenyl-rich organosiloxane clusters and polyacrylonitrile polymers are expected to serve as internal and external carbon source, respectively. The formation of an interpenetrating and continuous carbon matrix network would not only synergistically offer an improved electrochemical accessibility of active sites but also alleviate the volume expansion effect during cycling. As a result, this new type of anode delivered a high reversible capacity, remarkable cycle stability as well as excellent high-rate capability. In particular, the L2-SiOx@C material has a high initial coulomb efficienc of 80.4% and, after 500 cycles, a capacity retention as high as 97.5% at 0.5 A g-1 with a reversible specific capacity of 654.5 mA h g-1.

Lithium Pre-Storage Enables High Initial Coulombic Efficiency and Stable Lithium-Enriched Silicon/Graphite Anode.

Application of silicon-based anodes is significantly challenged by low initial Coulombic efficiency (ICE) and poor cyclability. Traditional pre-lithiation reagents often pose safety concerns due to their unstable chemical nature. Achieving a balance between water-stability and high ICE in prelithiated silicon is a critical issue. Here, we present a lithium-enriched silicon/graphite material with an ultra-high ICE of ≥110 % through a high-stable lithium pre-storage methodology. Lithium pre-storage prepared a nano-drilled graphite material with surficial lithium functional groups, which can form chemical bonds with adjacent silicon during high-temperature sintering. This results in an unexpected O-Li-Si interaction, leading to in situ pre-lithiation of silicon nanoparticles and providing high stability in air and water. Additionally, the lithium-enriched silicon/graphite materials impart a combination of high ICE, high specific capacity (620 mAh g-1), and long cycling stability (>400 cycles). This study opens up a promising avenue for highly air- and water-stable silicon anode prelithiation methods.

Energy band modulation of Li2O-rGO core-shell as cathode sacrificial additive enables capacity enhancement of hard carbon anode in Li-ion batteries.

Lithium oxides (Li2O) possess a considerable theoretical capacity, rendering them highly promising as cathodic pre-lithiation additives. However, its decomposition voltage exceeds the charging cut-off voltage of most cathode materials, hindering its direct use as a cathode sacrificial additive. Herein, we design a facile and safe method to reduce the decomposition energy of Li2O at room temperature to offset the irreversible capacity loss by using a core-shell structured Li2O-reduced graphene oxide (rGO)-polyethylene glycol (PEG) composite (denoted as Li2O-rGO-PEG). The graphene oxide (GO) was heat-treated to remove oxygen functional groups to synthesize rGO, and then reacted with Li2O to form a Li2O-rGO composite. According to the DFT calculations, the density of states at the Fermi level of Li2O-rGO becomes continuous and features a metallic nature, which significantly improves the electrical conductivity of Li2O and facilitates electron conduction that modify the delithiation potential of Li2O. PEG was used to enhance the cohesive force between rGO and Li2O and to protect Li2O from atmospheric contamination. Moreover, in order to demonstrate the excellent pre-lithiation ability of Li2O-rGO-PEG composite, hard carbon (HC) with low initial coulombic efficiency (ICE) was used as the anode. In the application of LFP (Li2O)/HC full cell, Li2O was decomposed to Li+ to effectively improve the initial charge capacity from 149.7 to 200 mAh/g and discharge capacity from 104.2 to 147.5 mAh/g, which are 33.6 % and 41.6 % higher than those of the pristine LFP/HC full cell, respectively. The cathode pre-lithiation method proposed in this work is simple and environmentally friendly. The successful utilization of Li2O as a pre-lithiation additive effectively addressed the issue of low initial coulombic efficiency of the HC, indicating excellent prospects for practical applications.

Innovative Solutions for High-Performance Silicon Anodes in Lithium-Ion Batteries: Overcoming Challenges and Real-World Applications.

Silicon (Si) has emerged as a potent anode material for lithium-ion batteries (LIBs), but faces challenges like low electrical conductivity and significant volume changes during lithiation/delithiation, leading to material pulverization and capacity degradation. Recent research on nanostructured Si aims to mitigate volume expansion and enhance electrochemical performance, yet still grapples with issues like pulverization, unstable solid electrolyte interface (SEI) growth, and interparticle resistance. This review delves into innovative strategies for optimizing Si anodes' electrochemical performance via structural engineering, focusing on the synthesis of Si/C composites, engineering multidimensional nanostructures, and applying non-carbonaceous coatings. Forming a stable SEI is vital to prevent electrolyte decomposition and enhance Li+ transport, thereby stabilizing the Si anode interface and boosting cycling Coulombic efficiency. We also examine groundbreaking advancements such as self-healing polymers and advanced prelithiation methods to improve initial Coulombic efficiency and combat capacity loss. Our review uniquely provides a detailed examination of these strategies in real-world applications, moving beyond theoretical discussions. It offers a critical analysis of these approaches in terms of performance enhancement, scalability, and commercial feasibility. In conclusion, this review presents a comprehensive view and a forward-looking perspective on designing robust, high-performance Si-based anodes the next generation of LIBs.

The Potential Regulation of Working Anode for Long-Term Zero-Volt Storage at 37 °C in Li-Ion Batteries.

The advanced lithium-ion batteries that can tolerate zero-volt storage (ZVS) are in high demand for implantable medical devices and spacecraft. However, ZVS can raise the anode potential, leading to Cu current collector dissolution and solid-electrolyte interphase (SEI) degradation, especially at 37 °C. In this contribution, by quantitatively regulating the dosage of Li6CoO4 cathode additives, controllable potential of the working anode under abusive-discharge conditions is demonstrated. The addition of Li6CoO4 keeps zero-crossing potential (ZCP) and the potential of ZVS below 2.0 V (vs Li/Li+) for LiCoO2|mesocarbon microbead cells at 37 °C. The capacity retention ratio (CRR) increases from 69.1% and 35.9% to 98.6% and 90.8% after 10 and 20 days of ZVS, respectively. The Cu dissolution and SEI degradation are effectively suppressed, while the over-lithiated cathode exhibits high reversible capacity after ZVS. The limiting conditions of long-term ZVS are further explored and a corresponding guide map is designed. When quantitatively regulating ZCP and the potential in ZVS, Cu dissolution, SEI degradation, and irreversible conversion of the cathode constitute the limiting conditions. This contribution designs the most reasonable potential range for ZVS protection at 37 °C, and realizes the best CRR record through precise potential regulation for the first time.

Lithiophilic Chemistry Facilitated Ultrathin Lithium for Scalable Prelithiation.

Prelithiation plays a crucial role in advancing the development of high-energy-density batteries, and ultrathin lithium (UTL) has been proven to be a promising anode prelithiation reagent. However, there remains a need to explore an adjustable, efficient, and cost-effective method for manufacturing UTL. In this study, we introduce a method for producing UTL with adjustable thicknesses ranging from 1.5 to 10 µm through blade coating of molten lithium on poly(vinylidene fluoride)-modified copper current collectors. By employing the transfer-printing method, prelithiated graphite and Si-C composite electrodes are prepared, which exhibit significantly improved initial Coulombic efficiencies of 99.60% and 99.32% in half-cells, respectively. Moreover, the energy densities of Li(NiCoMn)1/3O2 and LiFePO4 full cells assembled with the prelithiated graphite electrodes increase by 13.1% and 23.6%, respectively.

Solution-Based Deep Prelithiation for Lithium-Ion Capacitors with High Energy Density.

Lithium-ion capacitors (LICs) exhibit superior power density and cyclability compared to lithium-ion batteries. However, the low initial Coulombic efficiency (ICE) of amorphous carbon anodes (e.g., hard carbon (HC) and soft carbon (SC)) limits the energy density of LICs by underutilizing cathode capacity. Here, a solution-based deep prelithiation strategy for carbon anodes is applied using a contact-ion pair dominant solution, offering high energy density based on a systematic electrode balancing based on the cathode capacity increased beyond the original theoretical limit. Increasing the anode ICE to 150% over 100%, the activated carbon (AC) capacity is doubled by activating Li+ cation storage, which unleashes rocking-chair LIC operation alongside the dual-ion-storage mechanism. The increased AC capacity results in an energy density of 106.6 Wh kg-1 AC+SC, equivalent to 281% of that of LICs without prelithiation. Moreover, this process lowers the cathode-anode mass ratio, reducing the cell thickness by 67% without compromising the cell capacity. This solution-based deep chemical prelithiation promises high-energy LICs based on transition metal-free, earth-abundant active materials to meet the practical demands of power-intensive applications.

The "In situ electrolyte" as a sustainable alternative for the realization of high-power devices.

The "in situ electrolyte" displays a concept for electric double-layer- as well as metal-ion capacitors in which the by-products formed during carbon synthesis serve directly as electrolyte salt to minimize waste. In this work, the concept is applied for lithium- and sodium-based systems realizing EDLCs containing aqueous, "Water in Salt" (up to 1.8 V) as well as organic (2.4 V) electrolytes. Via the mechanochemical synthesis, carbon materials with surface areas up to 2000 m2 g-1 and an optimal amount of remaining by-product are designed from the renewable resource lignin. Different cation-anion combinations are enabled by further modification directly inside the pores creating imide-based salts which are tracked by synchrotron in situ XRD. By the addition of solvents, the EDLCs show good capacitances up to 21 F g-1 combined with excellent rate performances and stabilities. Moreover, the LiTFSI loaded carbon as positive electrode introduces a new tunable lithium alternative for the pre-lithiation of Li-ion capacitors displaying a good rate performance and cyclability.

Interlayer Engineering and Prelithiation: Empowering Si Anodes for Low-Pressure-Operating All-Solid-State Batteries.

Silicon (Si) anodes, free from the dendritic growth concerns found in lithium (Li) metal anodes, offer a promising alternative for high-energy all-solid-state batteries (ASSBs). However, most advancements in Si anodes have been achieved under impractical high operating pressures, which can mask detrimental electrochemo-mechanical issues. Herein, we effectively address the challenges related to the low-pressure operation of Si anodes in ASSBs by introducing an silver (Ag) interlayer between the solid electrolyte layer (Li6PS5Cl) and anode and prelithiating the anodes. The Si composite electrodes, consisting of Si/polyvinylidene fluoride/carbon nanotubes, are optimized for suitable mechanical properties and electrical connectivity. Although the impact of the Ag interlayer is insignificant at an exceedingly high operating pressure of 70 MPa, it substantially enhances the interfacial contacts under a practical low operating pressure of 15 MPa. Thus, Ag-coated Si anodes outperform bare Si anodes (discharge capacity: 2430 vs 1560 mA h g-1). The robust interfacial contact is attributed to the deformable, adhesive properties and protective role of the in situ lithiated Ag interlayer, as evidenced by comprehensive ex situ analyses. Operando electrochemical pressiometry is used effectively to probe the strong interface for Ag-coated Si anodes. Furthermore, prelithiation through the thermal evaporation deposition of Li metal significantly improves the cycling performance.

Accelerating Sulfur Redox Kinetics by Electronic Modulation and Drifting Effects of Pre-Lithiation Electrocatalysts.

Efficient catalyst design is crucial for addressing the sluggish multi-step sulfur redox reaction (SRR) in lithium-sulfur batteries (LiSBs), which are among the promising candidates for the next-generation high-energy-density storage systems. However, the limited understanding of the underlying catalytic kinetic mechanisms and the lack of precise control over catalyst structures pose challenges in designing highly efficient catalysts, which hinder the LiSBs' practical application. Here, drawing inspiration from the theoretical calculations, the concept of precisely controlled pre-lithiation SRR electrocatalysts is proposed. The dual roles of channel and surface lithium in pre-lithiated 1T'-MoS2 are revealed, referred to as the "electronic modulation effect" and "drifting effect", respectively, both of which contribute to accelerating the SRR kinetics. As a result, the thus-designed 1T'-Lix MoS2 /CS cathode obtained by epitaxial growth of pre-lithiated 1T'-MoS2 on cubic Co9 S8 exhibits impressive performance with a high initial specific capacity of 1049.8 mAh g-1 , excellent rate-capability, and remarkable long-term cycling stability with a decay rate of only 0.019% per cycle over 1000 cycles at 3 C. This work highlights the importance of precise control in pre-lithiation parameters and the synergistic effects of channel and surface lithium, providing new valuable insights into the design and optimization of SRR electrocatalysts for high-performance LiSBs.

Effect of Electrochemical Pre-Lithiation on Layered Oxide Cathodes for Anode-Free Lithium-metal Batteries.

Due to high energy density and lower manufacturing cost, anode-free lithium-metal batteries (AFLMBs) are attracting increasing attention. The challenges for developing them lie in inferior Coulombic efficiency and short cycle life due to the highly reactive lithium metal. Herein, an electrochemical pre-lithiation strategy is applied to layered oxide cathodes, specifically LiNiO2 and LiCoO2 , aiming to provide an additional lithium source and understand the effect on the cathode structure for AFLMBs. The mechanism for accommodating the excess Li depends on the structural stability of the cathodes where LiNiO2 forms lithiated Li2 NiO2 with the excess lithium in the crystalline lattice while the excess lithium in LiCoO2 forms a Li2 O phase. More importantly, an optimal amount of Li excess is necessary to maintain decent cycle stability and specific capacity in AFLMB, with 40% excess Li for LiNiO2 and 150% for LiCoO2 . While the pre-lithiation process causes particle pulverization depending on the amount of Li excess, LiCoO2 offers a much better cycle performance than LiNiO2 with a promising capacity retention of 80% after 300 cycles in AFLMB (vs 76% after 100 cycles for 40% Li excess in LiNiO2 ). This study provides a promising avenue for developing tailor-made layered oxide cathodes for AFLMBs.

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. The used solutions are carefully selected, and the composition and nanostructure of the as-formed artificial SEIs are revealed by cryogenic electron microscopy and X-ray photoelectron spectroscopy. The electrochemical evaluation demonstrates the unique merits of this artificial SEI, especially for the fluorinated interphase, which not only enhances the interfacial ion transport but also increases the tolerance of the prelithiated electrode to the air. The treated graphite electrode shows an initial Coulombic efficiency of 129.4%, a high capacity of 170 mAh g-1 at 3 C, and negligible capacity decay after 200 cycles at 1 C. These findings not only provide a facile, universal, and controllable method to construct an artificial SEI but also enlighten the upgrade of battery fabrication and the alternative use of advanced electrolytes.