Xiangming He

Tsinghua University | TH · Lithium ion Battery Lab

Trace protic impurities, such as water and hydrofluoric acid (HF), can severely degrade the stable and long cycling of lithium batteries. Therefore, the costly water removal process is inevitably needed throughout production of lithium batteries, leaving the paradox that energy-saving lithium battery technology consumes nonnegligible amounts of ene...

Solid state potassium metal batteries are intriguing in grid-scale energy storage, benefiting from the low cost, safety and high energy density. However, their practical applications are impeded by poor K/solid electrolyte (SE) interfacial contact and limited capacity caused by the low K self-diffusion coefficient, dendrite growth, and the intrinsi...

For energy storage devices, high energy density, high power density, cycle stability, and safety are the development goals. Solid‐state lithium metal batteries, with both safety and high performance, have become a hot topic in recent research. Although each component of these batteries has been studied for decades, and their individual performance...

Li‐ion batteries (LIBs) that promise both safety and high energy density are critical for a new‐energy future. However, recent studies on battery thermal runaway (TR) suggest that the higher the energy is compressed in a battery, the thermal accidents with fires and explosions can occur in a more catastrophic way. This “trade‐off” between energy de...

Due to its quite high theoretical specific-energy density, FeF2 nanomaterial is a good candidate for the cathode material of high-energy lithium-ion batteries. The preparation of FeF2 nanomaterial is very important for its application. At present, the preparation process mostly involves high temperature and an inert atmosphere, which need special o...

Li‐ion batteries adopting layered cathodes can effectively alleviate the range limitations of electric vehicles. Unfortunately the scarcity of Co inhibits massive deployment of layered cathodes. Eliminating Co from layered cathodes is necessary to make a breakthrough in global application of electric vehicles. However, Co‐free layered cathodes face...

Rechargeable sodium‐carbon dioxide batteries utilize CO2 directly and use abundant and low‐cost sodium instead of lithium. Sodium carbonate is an important discharge product in Na‐CO2 batteries and its oxidative decomposition during charging determines cell performance (i.e., overpotentials and cyclability) but the decomposition mechanism has not b...

Solid Electrolyte Interphase Enabler In article number 2211958, Xiangming He, Li Wang and co‐workers review the mechanism of a typical salt additive in electrolyte, lithium difluorophosphate, for Li‐ion batteries at extreme working conditions. With this additive as an exemplar, this perspective presents the potential of salt additives as robust int...

Faced with the increasingly severe energy and environment issues, eco‐friendly and efficient energy storage/transformation technology has become a research hotspot. Due to the ion/electron‐sponge properties and superior catalytic performance, polyoxometalates (POMs) have broad prospects in improving the performance of electrodes and batteries. In t...

Highlights The current issues and recent advances in polymer/inorganic composite electrolytes are reviewed. The molecular interaction between different components in the composite environment is highlighted for designing high-performance polymer/inorganic composite electrolytes. Inorganic filler properties that affect polymer/inorganic composite el...

The line edge roughness (LER) is one of the most critical indicators of photoresist imaging performance, and its measurement using a reliable method is of great significance for lithography. However, most studies only investigate photoresist resolution and sensitivity because LER measurements require an expensive and not widely available critical d...

Lithium difluorophosphate (LiDFP) is among the most widely applicable additives used to construct a robust solid electrolyte interphase (SEI) on electrode, which can improve the cycling performance and rate performance of high‐voltage cathodes and Li metal anodes at extreme temperatures. Regarding the working mechanism of LiDFP, reasonable but divi...

With the rapid development of energy storage technology, solid‐state lithium batteries with high energy density, power density, and safety are considered as the ideal choice for the next generation of energy storage devices. Solid electrolytes have attracted considerable attention as key components of solid‐state batteries. Compared with inorganic...

Lithographic patterning, which utilizes the solubility switch of photoresists to convert optical signals into nanostructures on the substrate, is the primary top-down approach for nanoscale fabrication. However, the low light/electron-energy conversion efficiency severely limits the throughput of lithography. Thiol-ene reaction, as a photoinitiated...

Digital Twins In article number 2202660, Dongsheng Ren, Jingyi Qiu, Jingliang Wang, Xiangming He, Hao Zhang, and co‐workers propose a digital twin‐based approach for rational design of ultrahigh‐power LiFePO4/graphite lithium‐ion batteries. Model‐driven optimization of ultrahigh‐power LiFePO4/graphite batteries is successfully realized, aiming at t...

Manganese-based Olivine is a promising cathode candidate with high energy and low cost for Li-ion batteries (LIBs). Its rate capability and cyclability challenges still remain even with nano-size and carbon coating. Herein, an ultrahigh rate performance is achieved by introducing an affinitive conductor to enhance the interfacial electron transport...

Single‐Crystal NMC Cathodes In article number 2202022, Li Wang, Xiangming He, and co‐workers review the merits and drawbacks of single‐crystal NMC cathodes with traditional poly‐crystal materials. The remaining challenges and perspectives to enhance the electrochemical performance of single‐crystal NMC cathodes for electronic vehicle application ar...

Cell design is effective to improve the performances of lithium‐ion batteries (LIBs). For identifying the bottleneck of a full battery used for high‐rate charging/discharging, we developed a simple method, by a reference electrode in practical pouch cells, to quick obtain the polarizations of the cathode and the anode. For a Li(Ni0.6Co0.2Mn0.2)O2/g...

Lithium metal anodes (LMAs) show unique superiority for secondary batteries because they possess the lowest molar mass and reduction potential among metallic elements. It can diminish the large gap in energy density between secondary batteries and fossil fuels. However, notorious dendrite propagation gives rise to large volume expansion, low revers...

With the widespread applications of electric vehicles, power grid stabilization, and high‐pulsed power loads, high‐power lithium‐ion batteries (LIBs) are in urgent demand. However, the existing experimental‐based design of high‐power batteries is usually costly and inefficient, and provides limited information on the complex physicochemical process...

It has always been our unrelenting effort to continuously enhance the energy density of lithium-ion batteries (LIBs). Energy density of LIBs is generally improved by optimizing the electrode materials and battery architecture. Increasing the energy density based on existing facilities and technologies is still considerably challenging. Herein, we p...

Lithium‐Ion Batteries In article number 2201964, Li Wang, Xiangming He, and co‐workers report a bi‐continuous separator for safe lithium‐ion batteries. This work concludes that engineering the pore structure and thermomechanical properties, rather than simply improving the heat‐resistance, is of significant importance for the design of advanced sep...

Ethylene carbonate (EC)-free electrolyte is proposed to enhance the high-voltage and safety performances of practical pouch-type LiNi0.6Co0.2Mn0.2O2|Graphite (NCM622|Gr) cells. Herein, it was demonstrated that the EC-free electrolyte can effectively stabilize NCM622 cathode interface and well compatible with the graphite anode. At high operating vo...

LiNi0.5Mn1.5O4 (LNMO)/Li4Ti5O12 (LTO) spinel-spinel batteries have appealing features of high energy, high power and inherent safety. However, cycling high-voltage LNMO cathodes causes severe oxidation of conventional carbonate-based electrolytes and leads to extensive capacity decay. Herein, we report that a nonflammable all-fluorinated electrolyt...

Solid‐State Lithium Batteries In article number 2201762, Maoxiang Jing, Xiangming He, and co‐workers report a composite solid‐state electrolyte (CSE) formed by in‐situ polymerization of 1.3‐dioxolane (DOL) catalyzed by nano yttria stabilized zirconia. Excellent cycle stability provides a new research idea for the practical application of PDOL based...

To drive electrical vehicles for long‐range, the energy density of Li‐ion batteries must be further enhanced, which requires high‐energy cathode materials. Among them, Ni‐rich LiNixMnyCo1−x–yO2 (x > 0.5, NMC) is one of the most promising candidates. However, traditional poly‐crystal (PC) NMC materials, whose particles are secondary clusters consist...

The wetting process plays an important role in battery production efficiency and battery quality, including available energy density, cycling life, power, and battery consistency. A convenient and efficient method for characterizing electrolyte filling, which becomes more crucial for lithium-ion batteries (LIBs) with a large format or super energy...

Manganese-rich LiMn1-yFeyPO4 (e.g., LiMn0.7Fe0.3PO4) is emerging as the most promising olivine cathode material after LiFePO4, which has a current market demand of > 500000 tons per year. However, its commercial application is challenging because of its poor kinetic properties. Although nanocrystallization is a transformative paradigm for improving...

Lithium iron phosphate (LiFePO4) has been widely used due to its high theoretical capacity and good cycle stability, but lithium manganese phosphate (LiMnPO4) with a higher operating voltage (4.1 V) has not been used, so it is necessary to conduct theoretical research on its inherent performance improvement strategy. The large-scale application of...

Iron(II) fluoride (FeF2) is a promising candidate as the cathode material for lithium-ion batteries (LIBs) due to its quite high theoretical energy density compared with the commercial cathode materials like LiCoO2 and its abundance. However, the actual energy density of various FeF2 materials nowadays is lower than the theoretical one. The actual...

With continuous improvement of batteries in energy density, enhancing their safety is becoming increasingly urgent. Herein, practical high energy density LiNi0.8Mn0.1Co0.1O2|graphite‐SiO pouch cell with nonflammable localized high concentration electrolyte (LHCE) is proposed that presents unique self‐discharge characteristic before thermal runaway...

Layered LiNi0.6Co0.2Mn0.2O2 (NCM622) attracts widespread attention primarily due to its potential for high energy density and moderate thermal stability. However, the low initial coulombic efficiency (ICE) of the material limits the maximum utilization of their capacity. The capacity loss in the first cycle occurs under 4.0V and keep almost constan...

Localized high-concentration electrolytes (LHCEs) provide a new way to expand multifunctional electrolytes because of their unique physicochemical properties. LHCEs are generated when high-concentration electrolytes (HCEs) are diluted by antisolvents, while the effect of antisolvents on the lithium-ion solvation structure is negligible. Herein, usi...

High energy density solid‐state lithium batteries require good ionic conductive solid electrolytes (SE) and stable matching with high‐voltage electrode materials. Here, a highly homogeneous poly(1,3‐dioxolane) composite solid electrolyte (CSE) membrane that can satisfy the above‐mentioned requirements by in situ catalytic polymerization effect of y...

During the last decade, the rapid development of lithium‐ion battery (LIB) energy storage systems has provided significant support for the efficient operation of renewable energy stations. In the coming years, the service life demand of energy storage systems will be further increased to 30 years from the current 20 years on the basis of the equiva...

Formation of lithium dendrites and byproducts on the Li anode surface affects the performance and safety of lithium metal batteries (LMBs). In order to visually and semi-quantitatively analyze the lithium dendrites and byproducts, as well as their distributions and morphology on lithium anodes, we designed a first aggregation-induced emission (AIE)...

Lithium (Li) deposition behavior plays an important role in dendrite formation and the subsequent performance of lithium metal batteries. This work reveals the impact of the lithiophilic sites of lithium-alloy on the Li plating process via the first-principles calculations. We find that the Li deposition mechanisms on the Li metal and Li22Sn5 surfa...

High-energy lithium-ion batteries (LIBs) can be realized with high-capacity materials such as nickel-rich cathode, however, their reversible operation requires long-term cathode-electrolyte interfacial stability, especially for high temperature application, but how the cathode electrolyte interphases (CEIs) evolutes during operation is still a myst...

Thermal runaway (TR) failures of large-format lithium-ion battery systems related to fires and explosions have become a growing concern. Here, we design a smart ceramic–hydrogel nanocomposite that provides integrated thermal management, cooling, and fire insulation functionalities and enables full-lifecycle security. The glass–ceramic nanobelt spon...

For a long time, carbon has been an ideal material for various electrochemical energy storage devices and a key component in electrochemical energy storage systems due to its advantages of rich surface states, easy tenability, and good chemical stability. Stable and high-performance carbon materials can support future applications of high specific...

Thermal runaway (TR) is crucial for the safe application of lithium-ion batteries, especially for high-energy-density batteries, and thus should be investigated in detail. In this paper, the TR behaviors of the LiNi0.6Mn0.2Co0.2O2/graphite lithium-ion batteries under different states of charge (SoC) are studied, and the relationship between SoC and...

Ionic selectivity is of significant importance in both fundamental science and practical applications. For instance, an ion‐selective material allows the passage of a particular kind of ions while blocking the others, which could be used for purification of materials. Herein, the Li‐ion‐selectivity of a garnet‐type solid electrolyte is discussed by...

As a result of the extensive research and application of LiFePO4 (LFP) in the past > 20 years, there is now a relatively in-depth understanding of its structural stability, phase transition mechanism and electrochemical properties. However, the difficulties faced by further improving the performance of LFP due to its intrinsic low electronic and io...

As a result of the extensive research and application of LiFePO 4 (LFP) in the past > 20 years, there is now a relatively in-depth understanding of its structural stability, phase transition mechanism and electrochemical properties. However, the difficulties faced by further improving the performance of LFP due to its intrinsic low electronic and i...

The lifetime of Li-ion batteries (LIBs) is highly dependent on the imperceptible physical/chemical changes/reactions that occur on/between the electrodes and electrolyte. Therefore, reliable and repeatable high-precision detection of the imperceptible changes/reactions is extremely significant. High precision electrochemical measurements, such as h...

Anode-free batteries possess high energy density and avoid the use of reactive Li during battery fabrication, and thus are highly desirable for high energy density batteries. However, they encounter fast failure due to the inferior electrochemical reversibility. One main reason is the fast inactive Li accumulation caused by the coupling of side rea...

LiNi0.8Co0.1Mn0.1O2 (NCM811) | SiOx‐graphite (SiO‐Gr.) battery chemistry is of intensive attention because its achievable practical energy density is approaching impressively 300 Wh Kg‐1. However, it still suffers rapid capacity fades during repeated cycles, both chemical, electrochemical and mechanical irreversibility contribute. A comprehensive u...

Lithium ion batteries (LIBs) have swept the whole energy storage field. However, the current mainstream lithium batteries are difficult to operate stably at high temperature (>60°C) due to the decomposition of electrolyte and solid electrolyte interphase (SEI), the cathode metal elements dissolution behavior, and potential thermal runaway. Here, We...

Overall Water Splitting The development of Co‐free cathodes has become a focus in the lithium‐ion battery industry. In article number 2103894, Li Wang, Peng Bai, Hong Xu, Xiangming He and co‐workers offer a detailed and timely insight into the corresponding research progress on Co‐free cathodes of Li‐rich oxides, Ni‐rich layered oxides, and spinel...

Layered LiNixCoyMn1-x-yO2 (NCM, or NCMxy(1-x-y)) is a dominant family of cathode materials for lithium-ion batteries (LIBs) due to its high energy density. Among all NCM cathode materials, NCM622 possess the optimal energy density at high potential (≥ 4.6 V vs. Li/Li⁺). However, the practical application of NCM622 at high voltage (≥ 4.6 V) is limit...

Non-aqueous rechargeable aluminum-ion batteries (AIBs) are a promising candidate for grid-scale energy storage due to their high theoretical energy density, safety, environmental benignity, and the abundance of Al sources. However, the limited cathode capacity and the high price of ionic liquid electrolytes hinder their large-scale applications. He...

Lithium-ion batteries (LIBs) based on olivine LiFePO4 (LFP) offer long cycle/calendar life and good safety, making them one of the dominant batteries in energy storage stations and electric vehicles, especially in China. Yet scientists have a weak understanding of LFP cathode degradation, which restricts the further development of LFP materials and...

Three‐dimensional (3D) covalent organic frameworks (COFs) possess great potential applications in various fields. Constructing 3D COFs with large pore sizes is extremely challenging due to the interpenetration and collapse. Herein, we report a series of crystalline imine‐linked 3D COFs (3D‐bor‐COF‐1, 3D‐bor‐COF‐2, 3D‐bor‐COF‐3) with mesoporous chan...

With the rapid growth of global electro‐mobility, the demand for cobalt is rapidly increasing because it is currently an indispensable component of the cathode materials in lithium‐ion batteries (LIBs). However, the use of Co raises moral issues caused by its exploitation and the geographic limitations of Co resources may result in risking the supp...

Thermal runaway is a critical issue for the large application of lithium-ion batteries. Exothermic reactions between lithiated graphite and electrolyte play a crucial role in the thermal runaway of lithium-ion batteries. However, the role of each component in the electrolyte during the exothermic reactions with lithiated graphite has not been fully...

Separator, an ionic permeable and electronic insulating membrane between cathode and anode, plays a crucial role in the electrochemical and safety performance of batteries. However, the commercial polyolefin separators not only suffer from inevitable thermal shrinkage at elevated temperature, but also fail to inhibit the hidden chemical crosstalk o...

Lithium reactivity with electrolytes leads to their continuous consumption and dendrite growth, which constitute major obstacles to harnessing the tremendous energy of lithium-metal anode in a reversible manner. Considerable attention has been focused on inhibiting dendrite via interface and electrolyte engineering, while admitting electrolyte-lith...

For the first time, cotton fiber-shaped Cu2O nanoparticles were prepared onto the surface of a commercial copper (Cu) foil via a very simple immersion method at room temperature in which the soaking solution only contained CuSO4, Na2S2O3, and a very little amount of 1-butyl-3-methylimidazolium trifluoroacetate. In this work, the current collectors...

The practical use of LiCoO2 is limited to 50%~70% due to the dramatic volume shrinkage induced cracks and subsequent interface parasitic reactions at high voltage. However, the fundamental understanding of...

Graphite is the dominant anode material for lithium-ion batteries (LIBs), however, it still suffers from Li-plating when charging fast or at low temperature, and Li-plating is associated with performance fading and safety concerns. Herein, we clarify the mechanism of lithium evolution from graphite particles by over-lithiation cycle test, in-situ X...

With the pursuit of a high-specific-energy battery, lithium metal battery (LMB) that using lithium (Li) metal anode has attracted great attention in recent years. To achieve a stable, long-term cycle of LMB, various battery components, including electrolytes, separators and composite lithium anode, have been explored. The separator, although it doe...

This paper presents an effective approach to improve the electrochemical performance of LiNi0.5Mn1.5O4 as cathode material for Li-ion batteries, including Al doping in Mn-site, combined with the spray drying method in which soluble starch is added as a cheap and environmentally friendly template agent. The as-prepared LiNi0.5Mn1.45Al0.05O4 material...

Serious safety issues are impeding the widespread adoption of high‐energy lithium‐ion batteries for transportation electrification and large‐scale grid storage. Herein, a triple‐salt ethylene carbonate (EC) free electrolyte for high‐safety and high‐energy pouch‐type LiNi0.8Mn0.1Co0.1O2|graphite (NMC811|Gr) cells is reported. This EC‐free electrolyt...

Fluorinated electrolytes possess good antioxidant capacity that provides high compatibility to high‐voltage cathode and flame retardance; thus, they are considered as a promising solution for advanced lithium‐ion batteries carrying both high energy density and high safety. Moreover, the fluorinated electrolytes are widely used to form stable electr...

To the best of our knowledge, this is the first time to report the preparation of a dotted nanowire arrayed by 5 nm sized palladium and nickel composite nanoparticles (denoted as PdxNiy NPs) via a hydrothermal method using NU and PdO·H2O as the starting materials. The samples prepared at the mass ratio of NU to PdO·H2O 1:1, 1:2 and 2:1 were, respec...