Li-Sn Alloys Research Articles

Tin-based dual-modification enabling enhanced air stability and electrochemical performance for Li5.5PS4.5Cl1.5 in all-solid-state lithium metal batteries

As one of sulfide electrolytes, chlorine-rich lithium argyrodites (Li5.5PS4.5Cl1.5) have significant advantages as solid state electrolytes (SSEs) in all-solid-state batteries (ASSBs) due to their ultra-high conductivity. However, their practical application is limited by poor air stability and weak compatibility with Li metals. Herein, we enhance the performance of Li5.5PS4.5Cl1.5 by doping it with SnO2, resulting in the formation of the Li5.58P0.92Sn0.08S4.34O0.16Cl1.5 electrolyte. The introduction of Sn and O dopants forms strong Sn-S and P-O bonds in the electrolyte, replacing the sensitive P-S bonds and suppressing H2S release. Additionally, this doped electrolyte demonstrates an impressive Li-ion conductivity of 5.71 mS cm−1, a high critical current density of 2.9 mA cm−2, and significantly improved air and moisture stability. Moreover, the Sn dopant produces a Li-Sn alloy layer on the bare Li metal anode, endowing the ASSB with an initial discharge capacity of 146.7mAh/g at 0.2C and a capacity retention of 86.2 % after 200 cycles at 0.5C. Combining with a 10 wt% SnF2-treated Li metal anode to further strengthen the electrode interfacial stability by the in-situ formed Li-Sn and LiF derivatives, the resultant full cell delivers a promoted initial discharge capacity of 179.5mAh/g at 0.2C and a high discharge capacity of 112.2mAh/g after 300 cycles at 0.5C. The dual strategy of electrolyte doping and Li anode modification achieves a synergistic effect that enables the ASSB to exhibit superior electrochemical performance, providing an effective way of preparing stable sulfide-based SSEs for large-scale applications.

Lithiation: A Pathway to Strengthen Sodiophilic Metal Interlayer of 3D Metallic Skeleton for High-Performance Sodium Metal Anodes.

Constructing a three-dimensional (3D) skeleton with a sodiophilic-modified layer (SML) has been proven to be an effective strategy to alleviate excessive volumetric deformation and continuous dendrite growth for sodium (Na) metal anodes. However, the weak binding force and violent reaction between the SML and the 3D skeleton lead to numerous cracks/defects and even pulverization of the SML during repeated Na plating/stripping. Herein, a lithiation pathway is presented to construct a sodiophilic Li-Sn alloy layer onto a 3D copper mesh to strengthen the SML for stable Na metal anodes. The lithiation 3D skeleton exhibits superior sodiophilicity, higher charge-transfer efficiency, and lower ion-diffusion barrier, contributing to the homogenization of ion-electronic flux and Na deposition. Simultaneously, the dense Li-Sn alloy is more stable than the monometal Sn-layer, which effectively prevents damage to the SML and enhances the stability of the SML. As a result, the asymmetrical cell exhibits great performance with a negligible nucleation overpotential and a high average Coulombic efficiency of 99.4%. Moreover, the full cell assembled with Na3V2(PO4)3 cathode delivers superior capacity retention of 91.3% after 1000 cycles at a current of 3C.

Li-Sn Alloyed Layer Containing Artificial SEI on Li-Metal Anode for Superior Lithium Metal Batteries: Development and Understanding of Anode/Electrolyte Interfacial Phenomena

Modern civilization and cutting-edge technologies and tools are highly dependent on energy storage devices and demand efficient and long-lasting high-energy-density storage devices. Lithium metal batteries have surpassed their competitors concerning energy density due to their inherent high specific capacity (3860 mAh/g) and the lowest electrochemical potential (-3.04 V vs. standard hydrogen electrode), proving to be one of the most favorable energy storage devices for smart and mobile gadgets, electric automobiles, grid storage, etc. However, safety-threatening and performance-decay challenges associated with lithium metal anodes, such as lithium dendrite formation, uncontrolled parasitic reactions between Li-metal and electrolyte, low coulombic efficiency, dead Li-formation, etc., restrict its employment in practical batteries. The root cause of the dendrite formation is poor Li-ion conductivity of bulk lithium metal, which results in an uneven electric field distribution, leading to non-uniform Li deposition/stripping upon repeated charge/discharge. Herein, a facile chemical reduction process is being opted to fabricate a highly Li-ion diffusive Li-Sn-based artificial SEI layer on the lithium metal surface to prevail over the above-mentioned issues. Therefore, upon careful concentration investigation of reactants, 25 mM precursor concentration (SnCl4 in EC: DMC in 1:1 volume ration) demonstrated the best electrochemical performance, revealing a cumulative capacity of over 700 mAh/cm2 at a current density of 1 mA/cm2 for 1 h in a symmetric cell. Physical characterizations (XRD and SEM-EDS) showed a thin layer containing Li-Sn alloys along with LiCl formed at the lithium metal surface. Possessing high Li-ion diffusivity, Li-Sn alloyed hybrid anode illustrated a gradual decrease in the charge transfer resistance on increasing the concentration, thus, lower overpotential in symmetric cells, in contrast to pristine Li-metal. However, an increase in the electrical resistance has been observed on increasing the precursor concentration due to the presence of the insulating LiCl phase in the protective layer. Moreover, in-situ optical microscopy demonstrated more uniform and on-surface Li-deposition for the hybrid electrode, whereas mossy and dendritic growth on bare Li-metal. Full cells prepared with Li-Sn alloyed anode against NMC532 cathode illustrated stable cycling up to 150 cycles; contrastingly, the cell with pristine Li-metal showed a drastic capacity fade just after 100 cycles, demonstrating the inclination towards safer lithium metal batteries.

Realizing Ultrathin LiSn Alloy Anode by Tuning the Wettability of Molten Li for High-Energy-Density Batteries.

Despite being heralded as the "holy grail" of anodes for their high theoretical specific capacity, lithium (Li) metal anodes still face practical challenges due to difficulties in fabricating ultrathin Li with controllable thickness and suppressing Li dendrites growth. Herein, we introduce a simple and cost-effective dip-coating method to fabricate ultrathin lithium-tin (LiSn) anode with adjustable thicknesses ranging from 4.5 to 45 μm. The in situ formation of Li22Sn5 alloy improves the wettability of the molten Li, enabling the casting of ultrathin Li metal layers on different substrates. More importantly, the abundant Li22Sn5 lithiophilic sites significantly lower the nucleation overpotential, inducing uniform Li deposition and accelerating the electrochemical reaction at the interface. As a result, the symmetric cell assembled with LiSn-Cu electrodes can cycle stably for more than 120 h with a charge/discharge depth of 50%, which is 1.5 times longer than the lifespan of the pure Li anode. In the full cells paired with NCM cathode, the discharge specific capacity is improved from 13.84 to 70.31 mA h g-1 with the LiSn-Cu anode at 8 C. The LiSn-Cu||NCM full cell realized a high energy density of 724.9 Wh kg-1 at the active material level with an N/P ratio of 1.4.

Multiple protective layers for suppressing Li dendrite growth and improving the cycle life of anode-free lithium metal batteries

Anode-free lithium metal batteries (AFLMBs) have sparked considerable attention in recent years because of their potential for high energy density; however, they suffer from severe Li dendrite growth and unstable solid electrolyte interphase (SEI), which typically result in rapid capacity decay. Herein, we demonstrate a long-life anode-free pouch cell by designing a dual-coating protective layer (Cu-Sn@SFPH) electrode with Sn-coated Cu (denoted as Cu-Sn) as the bottom layer and SrF2 nanoparticles strengthened by poly (vinylidene fluoride)-co-hexafluoropropylene (PVDF-HFP) as the top layer. The in-situ formed LiF-rich SEI enables fast Li+ transfer, while the lithiophilic Li-Sn and Li-Sr alloy layers serve as nucleation seeds for uniform Li deposition. The dual-coated Cu electrode in the Cu-Sn@SFPH||Li cell exhibits remarkable cycling stability for more than 3,200 h at a capacity of 2 mAh cm−2. The NCM111||Cu-Sn@SFPH pouch cell demonstrates outstanding performance with a capacity retention of 72.1 % and an average Coulombic efficiency (CE) of 99.9 % for 120 cycles. Under practical conditions, with NCM cathodes and a lean electrolyte volume, this design strategy opens a new approach to AFLMBs.

High Rate and Low-Temperature Stable Lithium Metal Batteries Enabled by Lithiophilic 3D Cu-CuSn Porous Framework.

Lithium (Li) metal is regarded as the "Holy Grail" of anodes for high-energy rechargeable lithium batteries by virtue of its ultrahigh theoretical specific capacity and the lowest redox potential. However, the Li dendrite impedes the practical application of Li metal anodes. Herein, lithiophilic three-dimensional Cu-CuSn porous framework (3D Cu-CuSn) was fabricated by a vapor phase dealloying strategy via the difference in saturated vapor pressure between different metals and the Kirkendall effect. CuSn alloy sites were converted into LiSn alloy sites through the molten Li infusion method, and composite Li metal anodes (3D Cu-LiSn-Li) are achieved. Alloyed tin, as the bridge between the porous copper substrate and metallic Li, plays a critical role in optimizing Li nucleation and enhancing the fast lithium migration kinetics. This work demonstrates that lithiophilic binary copper alloys are an effective way to achieve room-temperature high rate performance and satisfied low-temperature cycling stability for Li metal batteries.

Fundamentals of liquid metal displacement reactions: Emf measurements of Na-Sn, Li-Sn, Mg-Sn, and Ca-Sn

The driving force of spontaneous displacement reactions between Na-Sn alloys and molten LiCl, MgCl2, and CaCl2 salts stems from the difference of chemical potential between Na and Li, Mg, or Ca in liquid Sn. However, fundamental thermodynamic data are absent. Herein, electromotive force (emf) values of Na-Sn, Li-Sn, Mg-Sn, and Ca-Sn alloys (electrodeposition of Na, Li, Mg, and Ca in liquid Sn via the coulometric titration) were measured in NaF-NaCl-NaI, LiF-LiCl, MgCl2-NaCl-KCl, and CaCl2-LiCl-NaCl salts respectively at 650 °C. The measured emf values of these alloys were normalized with respect to the Cl−/Cl2 potential that −3.14 V to −3.35 V for Na-Sn (mole fractions xNa = 0.02–0.30) alloy, −2.90 V to −3.21 V for Li-Sn (xLi = 0.02–0.30) alloy, −2.38 V to −2.45 V for Mg-Sn (xMg = 0.01–0.15) alloy, and −2.90 V to −3.06 V for Ca-Sn (xCa = 0.01–0.15) alloy. And Li20Sn, Mg10Sn, and Ca10Sn alloys were successful prepared by displacement reactions between Na20Sn alloys and LiCl-NaCl, MgCl2-NaCl, and CaCl2-NaCl salts, which offers theoretical guidelines for s-block elements extraction and separation.

Ex situ TEM observations of the SnB2O4 glass electrode in all-solid-state lithium-ion batteries after charge–discharge process

As an environmentally friendly Pb-free material, SnO–B2O3 glass is considered a next-generation negative-electrode active material for all-solid-state lithium-ion batteries. Using SnB2O4 (50SnO·50B2O3) as a negative-electrode active material, the all-solid-state cells exhibit a high initial discharge capacity of approximately 950 mAh g−1. In this study, the microstructures of the SnB2O4 glassy electrode composites are investigated to clarify the charge–discharge behavior and charge–discharge mechanisms of the SnB2O4 glassy electrode composites using transmission electron microscopy (TEM). Here, ex situ TEM observations capture Sn and Li–Sn alloy nanocrystallites in the amorphous matrix. Li+ is incorporated into Sn, and Li–Sn alloy nanocrystallites are formed after initial lithiation. Further, Li+ is extracted from Li–Sn alloys to form Sn nanocrystallites after initial delithiation. In particular, Sn is lithiated and delithiated during the first cycle. However, as the cycle number increases, the capacity deteriorates. Ex situ TEM observations further reveal that Li–Sn alloys remain unchanged even after delithiation, and the crystallite size increases significantly. It is thus found that the capacity deterioration is attributed to the irreversible Li insertion/extraction between Sn and Li–Sn alloys.

SnS2 quantum dot as bifunctional “electrolyte additive” for lithium metal anode

The practical application of lithium metal battery has been impeded by the uneven lithium deposition and lithium dendrite growth. In this work, the tin sulfide (SnS2) quantum dots (QDs) are dispersed in the electrolyte and used as “electrolyte additive” to help constructing the high-performance lithium metal anode. Prior to lithium deposition, the SnS2 QDs were reduced to satisfactory interface components Li2S and lithiophilic LiSn alloy during the activation process. The as-formed Li2S and LiSn alloy can stabilize the interface structure, facilitate efficient ion transportation, and induce uniform lithium nucleation. As expected, the Li//Cu half-cell using electrolyte containing SnS2 QDs shows obviously improved coulombic efficiency and symmetric cell cyclic performance, which can sustain for longer than 900 h at a current density of 1.0 mA cm−2 with ultra-low overpotential of 10 mV. Moreover, the full cell using LiFePO4 cathode exhibited both excellent rate capability and cycling performance, i.e., capacity retention of 96.7 % after 400 cycles at 1.0 C.

Polyacrylonitrile fibers network reinforced polymer electrolyte with Li-Sn alloy layer protected Li anode toward ultra-long cycle lifespan for room-temperature solid-state batteries

Poly(ethylene oxide) polymer electrolyte composited with high content of succinonitrile organic plasticizer has excellent ionic conductivity at room temperature. Unfortunately, the poor interface stability between this novel solid polymer electrolyte (SPE) and Li metal anode leads to limited cycling performance, which seriously hinders its commercial applications. Herein, the electrospun nanofibers framework of polyacrynitrile (PAN) is introduced as a three-dimensional polymer filler, which can not only provide a robust skeleton for improved mechanical stability, but also inhibit the growth of Li dendrites with increased Li ion transference number from 0.28 to 0.41. Meanwhile, the Li anode is modified via constructing a dense Li-Sn alloy layer, offering a perfectly passivated anode surface and eliminating the side reaction between metallic Li and SPE efficiently. Hence, the interface compatibility and structure stability between the anode and the polymer electrolyte are greatly improved in the prolongated cyclic testing due to the synergistic effect of PAN reinforced SPE and Li-Sn alloy layer coated Li. As a result, the symmetrical battery can cycle stably for 2400 h at 25 °C under 0.1 mA cm−2 and 0.1 mAh cm−2, while the LiFePO4 based full battery can keep a good capacity retention of 85 % even after 500 cycles at 0.5 C. This work demonstrates that the combination of modifying SPE and building advanced interface layer on the Li anode is an effective measure to optimize the room temperature cycling performance of polymer solid-state Li battery.

Spatially isolating Li+ reduction from Li deposition via a Li22Sn5 alloy protective layer for advanced Li metal anodes.

A Li alloy based artificial coating layer can improve the cyclic performance of Li metal anodes. However, the protective mechanism is not well clarified due to multiple components of the artificial layer and complicated interface in liquid electrolytes. Herein, a single-component Li22Sn5 alloy layer buffered Li anode is paired with a solid-state polymer electrolyte, where a metallic Sn film is sputtered onto the Li anode and the subsequent alloying reaction leads to the formation of a Li22Sn5 phase. During the striping/plating process, the thickness and composition of the Li-Sn alloy passivation layer remain unchanged. Meanwhile, Li+ ions are reduced on the top surface of the Li22Sn5 layer, then the reduced Li atoms immediately pass through the alloy layer, and finally dense Li deposition occurs beneath the protective layer, realizing spatial isolation of the electrochemical reduction of Li+ from Li nucleation/growth. This unique protection mechanism can principally avoid the formation of Li dendrites and efficiently mitigate irreversible reactions between the Li anode and the polymer electrolyte. The synergistic effects lead to a clean and flat surface of the protected Li electrode, enabling a prolonged cycle lifetime over 1300 h at 25 °C at 0.1 mA cm-2 and 0.1 mA h cm-2 in a configuration of symmetrical cells.

Heterogeneous Li-alloy interphase enabling Li compensation during cycling for high energy density batteries

Alloying elemental foil (e.g., Sn, Al, In, etc) anodes shows great promise for high-energy-density lithium (Li)-ion batteries due to their attractive capacities, low cost, and easy processability. The abundant Li loss, uneven electrochemical reactions, and continuous side reactions on cycling cause poor electrochemical performance. Herein, using Sn foil as a model system, we constructed a conformal heterogeneous Li-alloy interface alloying elemental foil (defined as “Sn/Li-LA”) with slightly higher delithiation potential than Li-Sn alloy. It could separate the electrolyte and active Li-Sn to suppress the side reactions between them, and meanwhile function as Li+ conductive layer to homogenize electrochemical reactions. Specially, an overpotential triggered Li compensation by Li-LA could extend the cycle life of batteries. As a result, the initial Coulombic efficiency of the Sn/Li-LA increased from 45.9% to 107.4%, and the average Coulombic efficiency increased from 98.6% to 99.5% for 350 cycles compared with the pristine Sn foil at 1 mA cm–2 and 1 mAh cm–2 in half cells, respectively. Full cells paired with LiNi0.6Co0.2Mn0.2O (∼15.3 mg cm–2) delivered high reversible capacities (∼180 mAh g–1, ∼2.8 mAh cm–2) with stable cycling for 230 cycles in sharp contrast to the pristine Sn anode (∼90 mAh g–1, 1.4 mAh cm–2). In situ construction of Li-LA interface with donable active Li provides an effective approach to address the Li loss and extend the lifespan of high-capacity anode for advanced Li-based batteries.

Tracking the phase transformation and microstructural evolution of Sn anode using operando synchrotron X-ray energy-dispersive diffraction and X-ray tomography

Tin (Sn) holds great promise as an anode material for next-generation lithium (Li) ion batteries but suffers from massive volume change and poor cycling performance. To clarify the dynamic chemical and microstructural evolution of Sn anode during lithiation and delithiation, synchrotron X-ray energy-dispersive diffraction and X-ray tomography are simultaneously employed during Li/Sn cell operation. The intermediate Li-Sn alloy phases during de/lithiation are identified, and their dynamic phase transformation is unraveled which is further correlated with the volume variation of the Sn at particle- and electrode-level. Moreover, we find that the Sn particle expansion/shrinkage induced particle displacement is anisotropic: the displacement perpendicular to the electrode surface (z-axis) is more pronounced compared to the directions (x- and y-axis) along the electrode surface. This anisotropic particle displacement leads to an anisotropic volume variation at the electrode level and eventually generates a net electrode expansion towards the separator after cycling, which could be one of the root causes of mechanical detachment and delamination of electrodes during long-term operation. The unraveled chemical evolution of Li-Sn and deep insights into the microstructural evolution of Sn anode provided here could guide future design and engineering of Sn and other alloy anodes for high energy density Li- and Na-ion batteries.

Sn Nanoparticles Anchored on Carbon Foam Prepared by a Facile Electrodeposition for Lithium Storage

As an anode material of lithium‐ion batteries (LIB), Sn has great application potential due to its high theoretical specific capacity. However, the Li–Sn alloying reaction causes serious volume expansion and destroys the electrode structure, resulting in a rapid capacity decay. Herein, a simple preparation method for the Sn–carbon composites (Sn/CF) is designed by electrodepositing Sn nanoparticles on 3D carbon foam (CF) derived from the carbonization of melamine. Sn/CF‐3h exhibits excellent electrochemical properties. At 1 A g−1, the specific capacity of Sn/CF‐3h remains 166.6 mAh g−1 with a high capacity retention of 85.4% even over 2000 cycles. The designed structure of the Sn/CF electrode contributes to its excellent performance: providing a 3D conductive network, accommodating volume changes to prevent Sn nanoparticles from losing electrical contact, and promoting contact with electrolyte to accelerate lithium ion transmission.

Lithiophilic SnF2 modification on carbon fiber cloth enabling uniform Li deposition for stable lithium metal anodes

Lithium metal has been considered as the most attractive anode candidate for high-energy-density rechargeable batteries. Nevertheless, its infinite volume change and uncontrollable dendrite growth still pose a significant challenge for practical application. Herein, lithiophilic SnF2 modification on carbon fiber cloth is rationally designed to in situ form Li-Sn alloy active sites and LiF protective layer (named as Li/Li-Sn/CF electrode). The Li-Sn alloy with high ionic diffusion coefficient endows fast kinetics for homogeneous Li transfer and eliminates the random dendrite nuclei, as well as subsequently facilitates the uniform Li deposition. The LiF protective layer on the electrode can not only isolate the active Li from the electrolyte and retard the parasitic reactions, but also inhibit the dendrite growth and stabilize solid-electrolyte interphase (SEI) film due to its electronic insulative property and excellent mechanical strength. Furthermore, stabilized by the 3D carbon skeleton, the electrode can accommodate large volume variation during long-term galvanostatic cycling. Benefiting from these merits, the symmetric cell of Li/Li-Sn/CF exhibits a stable overpotential about 25 mV for over 1000 h at a current density of 1 mA cm−2 with a fixed areal capacity of 1 mA h cm−2. Impressively, the Li/Li‐Sn/CF||LFP full cells also achieve superior cycling stability and improved rate performance.

A dimensionally stable lithium alloy based composite electrode for lithium metal batteries

Lithium (Li) metal is regarded as the most promising anode material for next-generation secondary batteries due to its high theoretical specific capacity and low potential. However, the huge volume change and uncontrollable dendrites growth lead to its structural instability during charge/discharge processes. Herein, a lithium alloy-based composite (Li-Sn-Bi) is fabricated for the first time, by fusing Li metal and low melting Sn-Bi eutectic alloy to address the structural change of Li electrodes. In this composite electrode, Li3Bi alloy exhibits a skeleton structure that can alleviate dimensional change of the electrode, meanwhile Li-Sn alloys (Li22Sn5 and Li5Sn2) are embedded in the Li3Bi skeleton that uniform Li plating owing to their low lithium mass-transfer barriers. Thus, the Li-Sn-Bi electrode can preserve its structural integrity during the redox process by combining the respective role of each alloy. Notably, the lifespan of the symmetric battery with Li-Sn-Bi electrode exceeds 4000 h under a fixed capacity of 3 mAh cm−2 and sustains 2000 cycles at a high current density of 30 mA cm−2. This work provides a facile method to fabricate dimensionally stable Li composite electrodes for high-energy–density secondary lithium batteries.

Seamlessly integrated alloy-polymer interphase for high-rate and long-life lithium metal anodes

Reasonably designed artificial solid-electrolyte interphases (ASEI) are essential for reversible and stable lithium metal batteries. However, poor compatibility between heterogeneous interfaces remains a challenge for the ASEI to sustain the long-term stability of the lithium metal anodes. Herein, an interfacial compatible protective layer with interpenetrating Li–Sn alloy across the PVDF-HFP interphase (ISPI) is fabricated on the lithium to realize seamless integration of the organic/inorganic components in the interphase, and the interface between ASEI and metallic Li simultaneously. Compared to the double-layered and uniform protective layers that both have sharp joint interfaces, ISPI achieves enhanced mechanical stability and ensures homogeneous lithium deposition underneath it even with a high capacity of 5.0 mAh/cm2. Utilizing this interface-compatible ISPI-Li anode, the Li│Li symmetric cells perform stably at a super high current density of 20 mA/cm2 with a capacity of 1 mAh/cm2 for over 1000 cycles, and the full cells with ISPI-Li anodes exhibit outstanding cycling performance when coupling with LiFePO4 or LiNi0.8Co0.1Mn0.1O2 (NCM811) cathodes. This work proposes a significant concept of designing artificial SEI with a seamlessly integrated interface for lithium metal anodes and uncovers the basic mechanism of interfacial compatibility as a key factor in achieving a highly reversible lithium anode for the practical usage of LMBs.

In-situ polymerization with dual-function electrolyte additive toward future lithium metal batteries

As a promising choice of next-generation energy storage system, high-energy lithium metal batteries (LMBs) are facing degradation and safety problems mainly caused by undesired side reactions and growth of lithium dendrite. Thus, electrode design, modification of electrode interphase and electrolyte have therefore become key issues for future LMBs. Herein, we report that introducing a dual-function electrolyte additive, tin trifluoromethanesulfonate (Sn(OTf)2), into DOL-based electrolyte can in-situ fabricate poly(1,3-dioxolane) gel polymer electrolyte and a Li–Sn alloy anode interphase. The formed quasi-solid LMB utilizing various cathodes, including LiFePO4, sulfide, and LiCoO2, presents low internal resistance, robust and compatible interface as well as satisfying thermal, mechanical, and electrochemical stability even in air. This work provides a facile and accessible approach to manufacture qualified quasi-solid LMBs with improved safety and elongated lifetime.

Study of liquid tin-lithium alloy interaction with structural materials of fusion reactor at high temperatures

The paper presents the experimental studies to determine the corrosion compatibility of various base materials of the capillary-porous structures (CPS) with a liquid tin-lithium alloy under high temperatures. The experiments were carried out with Li-Sn alloy and the samples of vanadium, tungsten, molybdenum, tantalum, and stainless steel. These materials were selected as the candidate ones for the matrix of Li-Sn CPS prototypes. Manufacture of Li-Sn alloy and experiments were carried out at test bench VIKA. The ranges of the temperatures was: 600 °C–800 °C for stainless steel, and 850 °C–1000 °C for other metals; exposure time for every temperature step was up to 100 h.The implemented activities included manufacture of Sn-Li alloys with various lithium contents (25 at.% and 27 at.%), characterization of the samples, experiments to study compatibility of liquid tin-lithium with vanadium, tungsten, molybdenum, tantalum at temperatures of 850 °C–1000 °C, and stainless steel at temperatures of 600–800 °C. As a result of the performed activities, molybdenum and tungsten were selected as the most corrosion resistant materials in respect to Li-Sn alloys.

The catalysis of (de)lithiation in a nerve-cell-like anode of Li-ion battery

The Li2O intermedium generated in SnO2-based anode materials can increase the Li adsorption energy in lithiation, and it amorphizes the Li–Sn alloy that accelerates delithiation.