Low-Pressure and Durable Interface Design for Sulfide All-Solid-State Battery

2026-09-22 | Jerry Huang

Editor's note: On April 21, 2026, Academician Xueliang Sun and Changhong Wang's team at Eastern Institute of Technology, Ningbo published a research article entitled "Ionic Elastomer Interface for Low-Pressure and Durable All-Solid-State Batteries" in Advanced Energy Materials. This study proposes an ionically conductive elastomer interface strategy that constructs a composite interface combining mechanical flexibility with ionic conductivity, enabling stable operation of all-solid-state batteries (ASSBs) under low external pressure. The designed ionic elastomer, composed of SIBS (styrene-isobutylene-styrene block copolymer) and LiTFSI-G3 (lithium bis(trifluoromethanesulfonyl)imide with triglyme), exhibits outstanding comprehensive performance: a room-temperature ionic conductivity of 0.3 mS cm⁻¹, a composite electrolyte conductivity as high as 5.23 mS cm⁻¹, a low elastic modulus of 29.8 MPa, and excellent thermal stability (≥400 °C). Leveraging this interface design, the battery delivers an initial capacity of 200 mAh g⁻¹ at a low stack pressure of only 5 MPa and achieves stable cycling for over 700 cycles at 1C rate. Thanks to researchers’ efforts to bring a key solution about the interface treatment in sulfide-based ASSB.

Abstract

All-solid-state batteries (ASSBs) hold significant promise as next-generation energy storage systems due to their high energy density and intrinsic safety. However, their practical deployment is impeded by the need for high external pressure (typically tens of megapascals) to maintain solid–solid interfacial contact and ensure long-term cycling stability. Here, we report an ionic elastomer specifically designed to enable stable ASSB operation under substantially reduced stack pressure. The elastomer combines a mechanically flexible polymer matrix with an ionically conductive phase, delivering high room-temperature ionic conductivity (0.3 mS cm−1), a low elastic modulus (29.8 MPa), excellent thermal stability (≥400°C), and strong chemical compatibility with sulfide-based solid-state electrolytes (SSEs). When integrated with sulfide SSEs, the composite exhibits a remarkable room-temperature ionic conductivity of 5.23 mS cm−1. Incorporation of this composite into ASSBs with high-nickel cathodes (Ni ≥ 90%) yields an initial capacity of 200 mAh g−1 at 0.05C and outstanding cycling stability over 700 cycles at 1C under a low stack pressure of just 5 MPa. This ionic-elastomer strategy mitigates electrochemical-mechanical degradation, eliminates the high-pressure requirement, and offers a scalable pathway toward practical, durable ASSBs technologies.

Let’s look back at the current solid-solid interface challenges in sulfide-based ASSB:

The solid-solid interface problem in sulfide-based all-solid-state batteries fundamentally stems from the inability of solids to "wet" and conformally adhere to one another the way liquid electrolytes do, resulting in poor contact, excessive interfacial reactions, and crack formation. This represents the most formidable hurdle in transitioning sulfide ASSBs from the laboratory to mass production. The specific challenges can be categorized into three classes: physical contact deficiency, chemical side reactions, and mechanical failure.

One. Poor Physical Contact — "Open Circuit" of Ion Pathways

Point contact: Both cathode and electrolyte particles are rigid solids; after mixing, they can only form point-to-point contact with abundant interfacial voids, leading to obstructed lithium-ion transport channels and high interfacial impedance.

No self-healing capability: In liquid batteries, the electrolyte flows to fill gaps as electrodes expand and contract; once a solid-solid interface detaches, the disconnection is permanent.

Two. Abundant Chemical Side Reactions — Interface "Poisoning"

Cathode side: Under high voltages, sulfide electrolytes are prone to oxidation and react with cathode materials to form low-conductivity interfacial layers (e.g., Li₂S, P₂Sₓ). A "space-charge layer" also forms — lithium ions are depleted at the interface, something like a sudden speed-limit zone on a highway, causing a dramatic increase in impedance.

Anode side: In contact with lithium metal, reduction reactions readily occur, producing high-impedance byproducts and promoting lithium dendrite growth along grain boundaries that can penetrate the electrolyte and cause short circuits.

Three. Mechanical Failure — "Disintegration" After Cycling

Volume changes: During charge and discharge, electrode materials undergo expansion and contraction (silicon anodes can swell by over 300%). After hundreds of cycles, the solid-solid contact surfaces crack and delaminate, leading to a diving in capacity.

Requirement for external pressure: In the laboratory, interfacial contact can be forcibly maintained by applying tens to hundreds of megapascals of external stack pressure. However, such pressurization systems cannot be deployed in vehicles. Achieving stable contact under zero or low pressure during mass production remains a formidable engineering challenge.

Notably, sulfide electrolytes are extremely sensitive to moisture — exposure to water releases toxic H₂S gas. This necessitates that the entire manufacturing process be conducted under inert atmosphere or ultra-low dew-point conditions, further compounding the difficulty of interface engineering.

Reference

https://doi.org/10.1002/aenm.202504652

Newly Designed Electrolytes Enable Lithium Batteries With Energy Density Over 700 Wh/kg

2026-03-27 | Jerry Huang

Editor’s Note: Newly synthesized materials provide opportunities for novel electrolytes that enable lithium-metal pouch cells to achieve energy densities greater than 700 Wh/kg at room temperature and about 400 Wh/kg at -50 °C. Lithium salt LiFSI plays a very positive role in the electrolyte designs. Thanks so much to the great research and approach by Academician Jun Chen and Qing Zhao team from Nankai University. What difference and inspirations their research may bring us? Let's take a look at it.

Abstract

Electrolyte solvents for electrochemical devices have been dominated by oxygen (O)-based and nitrogen (N)-based ligands over the past decades, for which the dipole–ion (Li+, Na+ and so on) interaction usually lays the foundations of ion dissociation and transport but frustrates the charge transfer process at the electrolyte–electrode interface. Here, by synthesizing alkanes with monofluorinated structures, we show that fluorine (F)-based ligands with designed steric hindrance and Lewis basicity enable salt dissolution of more than 2 mol/L. Among them, 1,3-difluoro-propane (DFP)-based Li-ion electrolyte is endowed with all merits for energy-dense and low-temperature batteries, including low viscosity (0.95 cp), high oxidation stability (>4.9 V) and ionic conductivity of 0.29 mS/cm at −70 °C. By incorporating F atoms in the first solvation shell, the weak F–Li+ coordination facilitates the Li plating/stripping process with Coulombic efficiency (CE) up to 99.7% and exchange current density one magnitude larger than O–Li+ coordination at −50 °C. The electrolytes further enable the operation of lithium-metal pouch cells under an electrolyte amount of less than 0.5 g/Ah, achieving energy densities greater than 700 Wh/kg at room temperature and about 400 Wh/kg at −50 °C. The hydrofluorocarbon (HFC) electrolytes in this work provide a feasible approach to building electrochemical systems beyond traditional coordination chemistry.

Reference

https://doi.org/10.1038/s41586-026-10210-6

Breaking: Full Charge In 5 Minutes Scalable Solid State Battery Unveiled At CES 2026

2026-01-07 | Jerry Huang

News from Consumer Electronics Show (CES) 2026 in Las Vegas, a Finnish startup Donut Lab showcased their explosive "high-tech" product at the annual CES exhibition - this company claims its battery to be the world's first mass-produced all-solid-state battery (ASSB). At the 2026 CES exhibition, Donut Lab announced the launch of what it calls the world's first all-solid-state battery, which is ready for OEM production and will be the first type to be applied to Verge Motorcycles' TS Pro and Ultra, two wheeled motorcycle models. If they are truly delivered to customers, this will be an important milestone in the global electrification path, marking the transition of solid-state technology from the laboratory to mass production models. In a press release on its official website, Donut Lab stated that it is committed to innovating and delivering new forms of electrification solutions by pushing unceasingly the limits of electric vehicles’ performance and bringing new technology to the market. Donut Lab is shaping the future of mobility. "Now, Donut Lab is honored to launch the world's first all solid state battery that can be used for OEM vehicle manufacturing. The Donut Lab solid-state battery will be immediately put into commercial application, providing power for the existing lineup of Verge motorcycles.”

According to reports, Donut Lab's all-solid-state battery provides an energy density of 400Wh/kg, enabling longer range, lighter structure, and unprecedented flexibility in vehicle and product design.

The battery can be fully charged in just 5 minutes without the need to limit charging to 80%, and it supports safe, repetitive, and reliable full discharge.

Unlike traditional lithium-ion batteries, this all-solid-state battery offers “minimal capacity fade” over its lifetime. It is claimed to have tested up to 100,000 charge cycles, providing an actual lifespan far beyond existing technologies. Safety is another core of its features: no flammable liquid electrolytes, no thermal runaway and no metal dendrites! This fundamentally eliminates the cause of battery fires, making it extremely safe and truly revolutionary. Donut Lab stated that the performance of the battery has been rigorously tested in temperatures ranging from -30 to over 100 degrees C (retaining 99 percent capacity “with no signs of ignition or degradation”).

In terms of raw materials and costs, Donut Lab states that its solid-state batteries are entirely made from “abundant, affordable and geopolitically safe materials”, free of rare elements, cost less than lithium-ion alternatives. However, Donut Lab does not specify the specific materials required to produce their all-solid-state battery cell.

Antuan Goodwin, a senior automotive industry journalist, has had a close encounter with Donut Lab's all solid-state battery model at this year's CES exhibition. According to his introduction, this battery size is similar to a large screen smartphone (such as the iPhone 17 Pro Max), and it is extremely lightweight. This ultra light battery will also be very suitable for application in drones in the future.

According to its plan, Donut Lab is to build a solution to combine these batteries into larger 5 kWh power units; and each unit is of similar size to the PS5 gaming console. Its small size will allow an installation of four such power units into the frame of the Verge TS Pro motorcycle. This breakthrough design benefits from a circular electric motor integrated in the wheel announced by Donut Lab last year. Donut Lab and Verge Motorcycles announced on Monday that Verge motorcycles will be the world's first mass-produced vehicle equipped with this new battery. The motorcycle features a charging time of only 10 minutes, providing a comprehensive range of up to 60 kilometers per minute of charging. And their version Verge Ultra can travel up to 600 kilometers on a single charge. A 100,000 cycle life of this battery can be interpreted to a theoretical total range of 60 million kilometers. Even if it is driven 60000 kilometers per year, this battery can theoretically last for 1000 years. Some say, this sounds “too good to be true.”

“Donut Lab has engineered a new high performance solid state Donut Battery that can be scaled to major production volumes and seen now in real world use in the Verge Motorcycles bikes out on the road in Q1 2026.” The price for Verge TS Pro starts from $29900. Besides the installation in electric motorcycles, solid-state battery is obviously more promising in the application of electric vehicles. Goodwin stated that the advantages of this technology are more significant in large vehicles - the weight reduction and charging speed improvement will show a doubling effect in use. Donut Lab announced on Monday that it will collaborate with electric vehicle company WattEV to create an ultra lightweight modular electric vehicle platform that combines Donut motor and battery technology.

"Solid-state batteries have always been described as ‘just a few years away,'" Donut Lab chief executive Marko Lehtimäki said. "Our answer is different. They're ready today. Not later."

For better understanding, let's take a look at the current batteries in commercial use. There has always been the "(Mundellian) Trilemma" or "The Impossible Trinity" in the battery industry, which refers to the difficulty of simultaneously balancing the three core indicators of batteries (performance, cost and safety). Optimizing one of them often requires sacrificing the other or even two.

In comparison, the energy density of top commercial lithium-ion batteries ranges from approximately 250 to 300 Wh/kg, with a typical lifespan of around 5000 cycles. To extend battery life, it is often not recommended to charge them higher than 80%. If all features of Donut battery are true, it basically surpasses existing technology in every dimension.

What progress have other battery manufacturers made so far? What their plans might be for mass production of their ASSB? Sunwoda announced in October 2025 a new generation polymer solid-state battery with an energy density of 400Wh/kg, which has a lifespan of only 1200 cycles; The second-generation Shenxing super battery released by CATL in April 2025 has also been commercialized with a range of 520 kilometers in 5-minute charging. The cycle life of its fifth generation LFP battery is approximately over 3000 cycles.

Toyota initially planned for mass production of its all-solid-state battery in 2020, but later it was postponed to 2023 and then to 2026, now 2027-2028. Samsung SDI has also set its goal of scalable all-solid-state battery in 2027.

CATL has a plan that their small-scale production of all-solid-state battery will be carried out in 2027 and large-scale in around 2030. Hyundai and Kia say that it will not be earlier than 2030. Bloomberg NEF predicts that even by 2035, all solid state batteries will only enjoy about 10% of global share from electric vehicles and energy storage installations.

Investors And Consulting Firms Keep Optimistic On Lithium Demand In 2026

2025-12-17 | Jerry Huang

The global EV market has come to a relatively “rational” growth rate along with a worldwide decline of electric vehicle subsidies in last few years, bringing a weaker-than-expected demand for lithium salts during the same period of time.

Recently consulting firm Adamas Intelligence predicted that as the popularity of electric vehicles enters a relatively mature stage, the growth of energy storage demand will become the "key fluctuating factor" that will affect battery production, which will eventually shape lithium demand in 2026. Citigroup, UBS and Bernstein predict that this energy storage expansion will drive the global lithium market to be in short supply next year. Demand for lithium in energy storage segment is likely to grow by 55% next year, far outpacing the 19% increase in electric vehicles.

Another Low-cost and Green Technology Is Revealed for Recycling LIB Cathodes

2025-11-25 | Jerry Huang

Editor's note: The rapid development of consumer electronics, EV and grid energy storage has led to a huge demand for lithium-ion batteries (LIBs). However, with a lifespan of only 6-8 years, over 11 million tons of batteries are expected to expire by 2030, triggering unprecedented resource pressures, environmental risks and economic challenges. Currently, recycled cathode materials (particularly layered metal oxides, LMOs), containing high-value elements like Li, Co, Ni, and Mn, are the focus of these recycling efforts.

Here is another approach presented by Quanquan Pang team at PKU with joint Jiashen Meng team at WUT on recycling of spent LIB cathodes, particularly LMOs. Thanks to all researchers with high respect.

Notably, this LTMS-ECR approach directly processes spent cathodes still attached to aluminum current collectors, without the step to crush electrodes into "black powder" and significantly simplifying pretreatment steps.

LTMS-ECR technology is claimed to have the potential of achieving high profitability of $1.86/kg in recycling spent batteries due to its use of reusable low-cost molten salt electrolytes and Li2O, along with high-value by-products Co3O4 and LiCl, showing a nearly tenfold improvement over pyrometallurgical and hydrometallurgical technologies.

Analyses over technical, economic and environmental impact demonstrate that LTMS-ECR exhibits remarkable economic feasibility and carbon sustainability. Its high recovery efficiency, low energy consumption, and environmental friendliness present a revolutionary chemical pathway for cathode material recycling.

Abstract

Electrochemical recycling (ECR) offers a promising strategy that harnesses renewable energy to deconstruct spent layered metal oxides (LMOs). However, current ECR approaches are limited to high-temperature operation (up to 750 °C) employing alkali carbonate or chloride melts as electrolytes, leading to high energy consumption for heat input. Here, this study proposes a low-melting-point alkali chloroaluminate melt electrolyte composed of AlCl3–LiCl, enabling ECR electrolysis at a temperature as low as 150 °C. Owing to the high solubility of O2− charge carrier in alkali chloroaluminate melt, LMO cathode undergoes electrochemical reductive de-structuring to yield elemental transition metals and lithium chloride (LiCl). Importantly, two products are insoluble in the Li2O-added melt and can be separated by a facile water leaching treatment. Notably, by incorporating an inert TiN anode, CO2 emission during the electrolysis is eliminated by instead generating O2, further contributing to carbon neutrality. With the low-temperature molten salt electrolyte ECR (LTMS-ECR) approach, a high cobalt recovery rate of 97.3% is achieved for LiCoO2. Technoeconomic analyses project that the LTMS-ECR technology reduces energy consumption and CO2 emission by ≈20% and is nearly ten times more profitable compared to conventional methods. The approach represents a revolutionary alternative for energy-effective, sustainable and economically viable recycling of spent LIBs.

References

https://doi.org/10.1002/adma.202512984

What is happening in the lithium market especially LiPF6?

2025-10-31 | Jerry Huang

Over the past four months, many lithium salts including foundation salts like lithium carbonate and lithium hydroxide have had obvious increase in their market prices, so as the LiPF6 and LiFSI, based on supply and demand situation.

The energy storage demand of lithium salts from domestic market has been increasing fast in the second half of the year, together with growing demand of lithium batteries from EV market in a usual booming September and October makes great demand of lithium as well from battery manufacturers at almost full production rate. Surprisingly demands from overseas markets have also kept increasing. The strong demand from the market provides a supporting power for price increase of lithium salts. As LiPF6 is still a main salt for electrolyte in China market, its price has kept increasing fast, surpassing the price of LiFSI in October 2025. We have seen similar situation many times in history.

On the other hand, the price competition over last few years has brought an effect of a pause of production from a lot of medium and small sized lithium salt manufacturers; and some top producers have also stopped partial of their production capacity, restarting which will have to take two or three months. Many newly-planned plants and capacity have not been going as smoothly as expected. Lithium salts’ supply has become temporarily tight in the market after a period of overcapacity for a couple of years.

As the prices of the foundation lithium salts like lithium carbonate and lithium hydroxide have kept increasing during past four months, costs of LiPF6 and LiFSI have also increased at the same time.

So far the LiPF6 has been the main lithium salt for electrolyte production in China’s domestic market, which makes its demand stronger than other salts at the moment. Will the supply-demand unbalance continue to grow or get near to a balance in the near future? Let’s wait and see.

Poworks supplies high quality lithium carbonate, battery grade, technical or high purity, high quality lithium hydroxide, LiPF6 and LiFSI at full speed. Feel free to get connected.

An Inexpensive High Energy Density And Long Cycle Life Halide Material Revealed

2025-09-09 | Jerry Huang

Editor's note: In the field of energy storage, all-solid-state batteries are regarded as the best solution of next-generation energy storage technology, yet their development has long been constrained by critical bottlenecks in electrode materials. Traditional all-solid-state batteries (ASSBs) typically feature electrodes composed of active materials, solid electrolytes, and conductive additives. However, those inactive components (occupying 40–50% of electrodes volume) not only reduce energy density, but also induce interfacial side reactions and increase lithium-ion transport tortuosity. Although “All-In-One” designs (materials exhibiting high conductivity and electrochemical activity) could resolve these problems, existing materials like oxides (low capacity) and sulfides (high cost) struggle to meet requirements for future markets. Halides offer advantages in low cost and high ionic conductivity, yet suffer from insufficient electronic conductivity and energy density. Therefore, developing all-in-one materials that combine high electrochemical performance, inexpensive scalability with mechanical stability has become a critical challenge.

Here is an excellent example. A team from the University of Western Ontario in Canada provides a revolutionary answer in their Nature study—they designed the world's first halide material, Li₁.₃Fe₁.₂Cl₄, featuring dynamic self-healing capability and three-in-one integration (cathode/electrolyte/conductor). Through reversible Fe²⁺/Fe³⁺ redox reactions and a unique brittle-to-ductile transition mechanism, this material retains 90% capacity after 3,000 cycles, achieving an electrode energy density of 529.3 Wh kg⁻¹ (scalable to 725.6 Wh kg⁻¹ with composite designs). More remarkably, its cost is only 26% of conventional electrodes. Synchrotron radiation together with atomic simulations revealed an iron migration-induced self-healing mechanism for the first time! This work not only releases a core material for all-solid-state batteries but also provides a paradigm-level case for all-in-one design integrating materials, mechanics, and electrochemistry. Thanks to great efforts from all researchers.

Abstract

All-solid-state batteries require advanced cathode designs to realize their potential for high energy density and economic viability. Integrated all-in-one cathodes, which eliminate inactive conductive additives and heterogeneous interfaces, hold promise for substantial energy and stability gains but are hindered by materials lacking sufficient Li+/e− conductivity, mechanical robustness and structural stability. Here we present Li1.3Fe1.2Cl4, a cost-effective halide material that overcomes these challenges. Leveraging reversible Fe2+/Fe3+ redox and rapid Li+/e− transport within its framework, Li1.3Fe1.2Cl4 achieves an electrode energy density of 529.3 Wh kg−1 versus Li+/Li. Critically, Li1.3Fe1.2Cl4 shows unique dynamic properties during cycling, including reversible local Fe migration and a brittle-to-ductile transition that confers self-healing behaviour. This enables exceptional cycling stability, maintaining 90% capacity retention for 3,000 cycles at a rate of 5 C. Integration of Li1.3Fe1.2Cl4 with a nickel-rich layered oxide further increases the energy density to 725.6 Wh kg−1. By harnessing the advantageous dynamic mechanical and diffusion properties of all-in-one halides, this work establishes all-in-one halides as an avenue for energy-dense, durable cathodes in next-generation all-solid-state batteries.

References

https://doi.org/10.1038/s41586-025-09153-1

Polymer Lithium Is Winning The Solid-State Battery Race?

2025-09-08 | Jerry Huang

Editor's note: There are four electrolyte types for solid-state lithium batteries: polymer, oxide, sulfide, and halide, each with distinct characteristics:

Polymer Lithium Electrolytes

Utilizing polymer materials as electrolytes, these offer both flexibility and high ionic conductivity, making them suitable as a transitional solution for semi-solid batteries. They exhibit good processability, though long-term cycling stability remains to be validated.

Lithium Oxide Electrolytes

Based on materials like lithium oxide, these electrolytes offer lower cost and good stability but exhibit relatively low ionic conductivity.

Lithium Sulfide Electrolytes

Centered on lithium sulfide compounds, these electrolytes feature high room-temperature conductivity and excellent interface compatibility, positioning them as the most commercially promising technology among all. However, sulfide materials suffer from poor chemical stability and high production costs.

Lithium Halide Electrolytes

Halide solid-state electrolytes exhibit high conductivity and oxidation resistance, but it remains in the laboratory level with unclear commercialization prospects.

Common Features

All-solid-state batteries replace traditional liquid electrolytes with inorganic powder materials, significantly enhancing safety and energy density. However, different technical routes exhibit substantial differences in cost and process maturity. For instance, while the sulfide route offers high conductivity, it suffers from poor chemical stability, whereas the polymer route faces challenges in cycle life performance. Some experts say that the large scale commercial production of ASS batteries will eventually rely on solutions from semiconductor industry, including thin-film deposition, production-line-level precision inspection and vacuum system, as well as other solutions such as thin-film & micro-nano structuring. It is believed that this process will still take seven to ten years to go.

Solid-state battery technology is now undergoing a critical transition from laboratory prototypes to industrialization, which is strongly looking forward to a systematic overhaul of its evaluation framework. The laboratory phase primarily focuses on electrochemical performance metrics (such as energy density, cycle life, and rate capability), while industrial-scale solid-state battery technology requires the establishment of multidimensional evaluation criteria:

1. Expanded Evaluations: Industrial applications must involve systemic factors including: scalability & feasibility (involving process compatibility, yield control, etc.), supply chain maturity (including critical raw material supply, specialized equipment support, etc.), and total lifecycle cost (covering raw material procurement, manufacturing, recycling, etc.).

2. Technology-Cost Optimization: Industrialization demands an optimal balance between technical data and cost, including dynamic balance between electrochemical performance and manufacturing costs, material selection and its supply chain resilience, balance between production process complexity and scalability.

3. Systematic evaluation: Compliance with key requirements including mass production consistency (6σ quality control standard), safety certifications (e.g., compliance with UL 9540A and other international standards) and capacity design of a single-production-line ≥2GWh, etc.

Professor Guo has a different view for polymer lithium's winning on solid-state battery race over lithium sulfide electrolytes. Let's take a look at the research from Xin Guo team. Thanks so much to those great efforts from all researchers.

Abstract

Solid-state batteries (SSBs) promise to revolutionize energy storage by offering enhanced safety, higher energy density, and improved cycle lifespan over conventional lithium-ion batteries. Among the various solid electrolytes, polymers stand out for their unique combination of processability, mechanical compliance, and chemical versatility. This review explores why polymers are poised to lead the race toward commercial SSBs. Their intrinsic advantages—such as superior interfacial contact with electrodes, tunable ionic conductivity, and compatibility with scalable manufacturing methods—as well as the key technical challenges they face, including limited thermal stability, narrow electrochemical windows, and interfacial degradation, are examined. This study highlights emerging solutions from recent research, including polymer molecular design, polymer–ceramic composites, and in situ polymerization strategies. In contrast to oxide and sulfide systems, which face significant barriers in cost, manufacturability, and integration, polymer-based electrolytes offer a realistic and economically viable path to large-scale deployment. With continuing advances in materials design and industrial processing, polymers are not only competitive—they are leading the transition to next-generation solid-state batteries.

References

https://doi.org/10.1002/advs.202510481

Breaking: Boron-Alloyed Silicon Anodes Triple The Calendar Life Of Lithium-Ion Batteries

2025-06-29 |

Abstract

Stabilizing the solid electrolyte interphase (SEI) remains a key challenge for silicon-based lithium-ion battery anodes. Alloying silicon with secondary elements like boron has emerged as a promising strategy to improve the cycle life of silicon anodes, yet the underlying mechanism remains unclear. To address this knowledge gap, how boron concentration influences battery performance is systematically investigated. These results show a near-monotonic increase in cycle lifetime with higher boron content, with boron-rich electrodes significantly outperforming pure silicon. Additionally, silicon-boron alloy anodes exhibit nearly three times longer calendar life than pure silicon. Through detailed mechanistic analysis, alternative contributing factors are systematically ruled out, and it is proposed that improved passivation arises from a strong permanent dipole at the nanoparticle surface. This dipole, formed by undercoordinated and highly Lewis acidic boron, creates a static, ion-dense layer that stabilizes the electrochemical interface, reducing parasitic electrolyte decomposition and enhancing long-term stability. These findings suggest that, within the SEI framework, the electric double layer is an important consideration in surface passivation. This insight provides an underexplored parameter space for optimizing silicon anodes in next-generation lithium-ion batteries.

Reference

https://doi.org/10.1002/aenm.202501074

How Does LiTFSI Make A Difference In Sodium-Metal Batteries?

2025-06-29 |

Editor's note: Sodium-metal batteries are important for large-scale energy storage and mobile electronic devices as an energy storage device with high energy density and low cost. However, the performance of electrolyte and SEI limits the cycle life and charge/discharge rate of sodium-metal batteries. How does LiTFSI make a difference in sodium-metal batteries? Here is an example. Thanks to a special research from Shuang Wan team.

Abstract

Constructing an inorganic-rich and robust solid electrolyte interphase (SEI) is one of the crucial approaches to improving the electrochemical performance of sodium metal batteries (SMBs). However, the low conductivity and distribution of common inorganics in SEI disturb Na+ diffusion and induce nonuniform sodium deposition. Here, we construct a unique SEI with evenly scattered high-conductivity inorganics by introducing a self-sacrifice LiTFSI into the sodium salt-base carbonate electrolyte. The reductive competition effect between LiTFSI and FEC facilitates the formation of the SEI with evenly scattered inorganics. In which the high-conductive Li3N and inorganics provide fast ions transport domains and high-flux nucleation sites for Na+, thus conducive to rapid sodium deposition at a high rate. Therefore, the SEI derived from LiTFSI and FEC enables the Na∥Na3V2(PO4)3 cell to show 89.15% capacity retention (87.62 mA h g–1) at an ultrahigh rate of 60 C after 10,000 cycles, while the cell without LiTFSI delivers only 48.44% capacity retention even after 8000 cycles. Moreover, the Na∥Na3V2(PO4)3 pouch cell with the special SEI presents a stable capacity retention of 92.05% at 10 C after 2000 cycles. This unique SEI design elucidates a new strategy to propel SMBs to operate under extreme high-rate conditions.

Copyright © 2023 American Chemical Society

Reference

https://pubs.acs.org/doi/10.1021/jacs.3c08224