High-capacity Lithium Batteries Research Articles

Is There Hope for Ni-Based Disordered Rock Salt Cathode Materials?

Li-ion batteries achieved in the last 3 decades extremely high energy densities, making them the energy storage devices of choice for the electrification of our society. Despite this improvement, their energy density is still low as compared to gasoline, motivating further research towards materials with better performances. State of the art positive electrodes are nowadays layered materials with a ratio Li:M of 1:1, with M being one or multiple transition metals. LiNiO2 is a noteworthy example. Disordered rock salt (DRX) materials were instead thought to be electrochemically inactive until the development of a percolation theory,1 which demonstrated that lithium-rich materials (Li:M>1.1) with a cation disordered rock-salt structure (DRX) can achieve high reversible specific capacities. The general formula of these lithium-rich compounds can be written as Li1+y(MM′)1−yO2 where the Li content ranges usually from 1.05 to 1.33. With M is indicated a redox active specie (Mn, Ni, Fe, Cr, V) and M’ is typically a d0 element, which is redox inactive during charge and discharge and well accommodates the disordered structure.2 Materials with such structures have been shown to deliver extremely high specific capacities, resulting in equally high specific energies.3 In our recent work we investigated two DRX compounds based on Ni-redox. First, Li2NiO3, which is layered (with monoclinic distortion), but that decomposes to a disordered rock salt structure with cycling. The material displays interesting defect chemistry but fast capacity fading.4 More recently, we developed a class of Li-rich compounds with the chemical composition Li2yNiyTi2-3yO2 (y = 0.50, 0.55, 0.60, 0.67). These samples were prepared via solid-state reaction at three different temperatures (700 °C, 800 °C, 900 °C). By X-ray and neutron diffraction, we demonstrated a pure phase solid solution at high temperature, yet, by decreasing the synthesis temperature and increasing the Li content, phase separation occurs into a rock salt-type and a Li2TiO3 phase. The synthesis process has been also verified by DFT and by in situ X-ray diffraction. In all DRX materials synthesized, the electrochemical performances revealed a strong voltage hysteresis between charge and discharge and fast capacity fade.5,6 This raises then the question of whether any Ni-based DRX material can provide high capacity, high rate capability and stability, while avoiding the commonly encountered large hysteresis, or whether this can only be achieved in Mn-based compounds. In this presentation, by discussing our own work and recent literature reports, we aim at answering this question. Bibliography Urban, Alexander, Jinhyuk Lee, and Gerbrand Ceder. “The Configurational Space of Rocksalt-Type Oxides for High-Capacity Lithium Battery Electrodes.” Advanced Energy Materials4, 13: 1400478.Chen, Dongchang, Juhyeon Ahn, and Guoying Chen. “An Overview of Cation-Disordered Lithium-Excess Rocksalt Cathodes.” ACS Energy Letters, 2021, 1358–76.Clément et al., Cation-disordered rocksalt transition metal oxides and oxyfluorides for high energy lithium-ion cathodes, Energy & Environmental Science, 2020, 13 (2), 345-373Bianchini et al., From LiNiO2 to Li2NiO3: Synthesis, Structures and Electrochemical Mechanisms in Li-Rich Nickel Oxides, Chem. Mater. 2020, 32, 9211−9227Reitano, et al. Manuscript submitted, 2024.Li, Biao, Khagesh Kumar, Indrani Roy, Anatolii V. Morozov, Olga V. Emelyanova, Leiting Zhang, Tuncay Koç, et al. “Capturing Dynamic Ligand-to-Metal Charge Transfer with a Long-Lived Cationic Intermediate for Anionic Redox.” Nature Materials21, 10: 1165–74.

Synergistic effect of LixSi/Li3N artificial interface and 3D framework for enabling Dendrite-free, long-life lithium metal anodes

Lithium metal is highly favored as an ideal anode material in future high-capacity lithium batteries due to its appealing properties. Nevertheless, the implementation of lithium metal batteries (LMBs) is severely plagued by challenges such as instable solid electrolyte interface (SEI), uncontrolled growth of dendrite, and severe volume expansion. Herein, to address the aforementioned issues, an artificial SEI layer is fabricated, which is comprised of LixSi alloy and Li3N. The in-situ generated LixSi/Li3N interface is formed on the carbon fiber (denoted as CF/LixSi/Li3N) through a spontaneous reaction between molten Li and Si3N4. Density functional theory (DFT) calculations reveal that LixSi alloy has low ion diffusion energy barrier, which facilitates the low nucleation overpotential of Li+ and enables homogeneous lithium deposition. Li3N can further promote the rapid Li+ transport due to the excellent Li+ conductivity. In addition, the reserved 3D space effectively mitigates the volume change along cycling procedure. Owing to the synergistic effect of the LixSi/Li3N protective layer and the 3D structure, the composite anode shows higher cycling stability with a lifetime of more than 3000 cycles at 1 mA cm−2. Furthermore, matched with commercial LiFePO4 (LFP) and LiNi5Co2Mn3O2 (NCM523) cathodes, the full cells also exhibit impressive electrochemical properties. This work introduces an ingenious approach for constructing stable lithium metal anodes and effective lithium metal batteries.

Adaptive Virtual Inertial Control and Virtual Droop Control Coordinated Control Strategy for Hybrid Energy Storage Taking into Account State of Charge Optimization

For energy-storage-assisting conventional units to participate in the primary frequency regulation of a power system, firstly, based on the frequency regulation mechanism of virtual inertial control (VIC) and virtual droop control (VDC) of energy storage, we analyze the effect of the action timing of energy storage on the frequency deviation of the grid under two control methods and put forward a reasonable combination of the two control methods; on this basis, we also put forward hybrid energy storage adaptive VIC and VDC based on the demand of VIC and VDC on the power and capacity of energy storage. On this basis, based on the demand of VIC and VDC on the power and capacity of energy storage, a hybrid energy storage adaptive VIC and VDC coordinated control strategy based on supercapacitor–lithium batteries is proposed, whereby a high-power storage supercapacitor responds to inertial control signals to rapidly suppress a drop in frequency, and the high-capacity lithium battery responds to droop control signals to perform long-time droop control. The high-capacity lithium battery responds to the sagging control signal and is used to perform a long-time sagging power response; finally, in order to avoid the state of charge (SOC) of energy storage falling into a low/high working condition and losing the subsequent frequency regulation ability, an adaptive power control strategy of energy storage based on the improved logistic function is proposed. The simulation results show that under typical load disturbance, the SOC level of the proposed strategy increases by 19.17% and 30.16%, respectively, compared with that of the single-lithium strategy and no energy storage, and the SOC level of the supercapacitor and lithium battery increases by 29.4% and 2.1%, respectively, compared with that of logistic optimization.

Synthesis, Structural and Electrochemical Investigation of Disordered Rock Salt Compounds Based on Ni and Ti

Li-ion batteries achieved in the last 3 decades extremely high energy densities, making them the energy storage devices of choice for the electrification of our society. Despite this improvement, their energy density is still low as compared to gasoline, motivating further research towards materials with better performances. State of the art positive electrodes are nowadays layered materials with a ratio Li:M of 1:1, with M being one or multiple transition metals. Disordered rock salt (DRX) materials without a layered structure were thought to be electrochemically inactive. With the development of the percolation theory, 1(Urban, Lee, and Ceder) it was demonstrated that lithium-rich materials (Li:M>1) with a cation disordered rock-salt structure (DRX) can achieve high reversible specific capacities. The general formula of these lithium-rich compounds can be written Li1+y(MM′)1−yO2 where the Li content ranges usually from 1.05 to 1.33, essential to promote Li percolation pathways. With M is indicated a redox active specie (Mn, Ni, Fe, Cr, V) and M’ is typically a d0 element, which is redox inactive during charge and discharge and therefore stabilizes the disordered structure and acting as charge compensator.2 (Chen, Ahn, and Chen)In this work a class of Li-rich compounds with the chemical composition Li2yNiyTi2-3yO2 has been investigated (y = 0.50, 0.55, 0.60, 0.67). These samples were prepared via solid-state reaction at three different temperatures (700 °C, 800 °C, 900 °C). X-ray diffraction has been used to determine the crystal structure of the samples, revealing a predominant rock salt-type phase. However, by decreasing the synthesis temperature and increasing the Li content, phase separation occurs into a rock salt-type and a Li2TiO3 phase. The synthesis has been also verified by DFT and by in situ X-ray diffraction. Neutron diffraction experiment have been carried out to fully understand the cationic distribution in the samples. Finally, the electrochemical performances of the samples have been investigated in Li half cells, revealing a strong voltage hysteresis between charge and discharge.3 (Li et al.) Bibliography Urban, Alexander, Jinhyuk Lee, and Gerbrand Ceder. “The Configurational Space of Rocksalt-Type Oxides for High-Capacity Lithium Battery Electrodes.” Advanced Energy Materials 4, no. 13 (September 2014): 1400478. https://doi.org/10.1002/aenm.201400478.Chen, Dongchang, Juhyeon Ahn, and Guoying Chen. “An Overview of Cation-Disordered Lithium-Excess Rocksalt Cathodes.” ACS Energy Letters, March 17, 2021, 1358–76. https://doi.org/10.1021/acsenergylett.1c00203.Li, Biao, Khagesh Kumar, Indrani Roy, Anatolii V. Morozov, Olga V. Emelyanova, Leiting Zhang, Tuncay Koç, et al. “Capturing Dynamic Ligand-to-Metal Charge Transfer with a Long-Lived Cationic Intermediate for Anionic Redox.” Nature Materials 21, no. 10 (October 2022): 1165–74. https://doi.org/10.1038/s41563-022-01278-2

Synthesis, characterization and electrochemical performance analysis of nanomaterials for high capacity lithium batteries

Synthesis, characterization and electrochemical performance analysis of nanomaterials for high capacity lithium batteries

Asbestos-functionalized solid polymer electrolyte for uniform Li deposition in lithium metal batteries

Lithium metal anode possesses promising prospects for the new generation of high-capacity lithium batteries. However, the hazardous lithium dendrite of Li metal leads to inferior cycling stability, which blocks their commercial applications. In this work, an asbestos (ASB) functionalized solid polymer electrolyte (SPE) is presented to facilitate even lithium deposition. The density functional theory calculations confirm that lithium ions (Li+) tend to adsorb on ASB rather than poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) during the deposition process, resulting in the optimization of Li+ distribution in the SPE and the uniform deposition of Li+, which suppresses lithium dendrite growth. The ionic conductivity and Li+ transference number (tLi+) of the ASB functionalized SPE at 30 ℃ are enhanced to 0.77 mS cm−1 and 0.63, respectively. After 300 cycles at 30 ℃, LiFePO4 battery with the ASB functionalized SPE reveals a discharge capacity of 133 mAh g−1 at 1 C. Besides, the even and smooth surface morphology of Li metal employed the ASB functionalized SPE after cycling demonstrates that the dendrite can be successfully inhibited. The ASB functionalized SPE proposes a prospective strategy for restraining lithium dendrite.

Low-potential and high-capacity lithium battery anode based on hierarchical assemblies of Na2TiSiO5 nanotubes

Titanium-based materials such as TiO2 and Li4Ti5O12 are promising candidates for next-generation lithium-ion batteries (LIBs), but the high operating potential and unsatisfactory specific capacity severely restrict the potential application prospects. Li2TiSiO5 as a novel anode has attracted great attention due to its low-potential and high-capacity properties, but the conversion transition of Li2TiSiO5 to Li4SiO4 and TiO during Li+ intercalation and de-intercalation unfavorably affects the structural stability and hinders Li+ transport. Herein, novel cocoon-like microspheres assembled by Na2TiSiO5 nanotubes (NTSO-T), as the substitute of Li2TiSiO5, are facilely synthesized through a hydrothermal reaction. The hierarchical structure could effectively facilitate the Li+ diffusion, reduces internal strain, and enhances structural stability without greatly reducing the tap density. With a low but safe operating potential of 0.75 V, NTSO-T anode exhibits a high reversible capacity of 400 mAh g−1 which exceeds most reported Ti-based anodes, and durable long-cycling performance (capacity retention after 3000 cycles reaches 77%). Most importantly, the rate capability of NTSO-T is significantly enhanced. Kinetic reaction analysis has demonstrated the pseudocapacitive contribution in NTSO-T anode dominates the lithium storage kinetics. In addition, ex situ XRD and Raman analysis reveal a partially reversible conversion mechanism occurring in the framework. The excellent electrochemical performance of NTSO-T provides a promising anode candidate for next-generation LIBs.

Preparation and electrochemical properties of benzothiadiazole-benzotriazole donor-acceptor conductive polymer lithium-ion anode materials

The specific capacity of conventional conducting polymer composite electrodes is small. Based on the characteristics of donor-acceptor (D-A) conducting polymers with a wide range of π-electron leaving domains, narrow band gap, high conductivity and excellent electrochemical properties, D-A polymer monomers OTTBT (4, 8-Bis(3,4-ethylenedioxythiophene-2-yl)-6-(2-ethylhexyl)-[1,2,5]thiadiazolo[3,4-f] benzotriazole) and TTBT (4, 8-Bis(thiophen-2-yl)-6-(2-ethylhexyl)-[1,2,5]thiadiazolo[3,4-f] benzotriazole) were synthesized by Stille cross-coupling reaction using benzothiadiazole-benzotriazole as the acceptor unit and EDOT (3,4-ethylenedioxythiophene) or thiophene as the donor unit. Each monomer was polymerized in situ on the surface of activated carbon (AC) to obtain POTTBT@AC and PTTBT@AC composite electrode materials, respectively. The results showed that the charge storage behavior of both composites was controlled by the pseudocapacitance process. POTTBT@AC had better specific capacity, rate performance and cycling stability than PTTBT@AC. The lithium-ion storage performance of POTTBT was significantly higher than that of PTTBT, probably due to the former's higher electron supply capacity, rigidity and co-planarity. Both electrode materials had good specific capacity and rate performance and were suitable as anode materials for lithium batteries. D-A conductive polymer provides a new idea for the synthesis of electrode materials for high-capacity lithium batteries.

Electronic Localization Derived Excellent Stability of Li Metal Anode with Ultrathin Alloy.

Lithium metal is an ideal anode for next‐generation high‐energy‐density batteries. However, lithium dendrite growth has impeded its commercial application. Herein, fabricating Li‐based ultrathin alloys with electronic localization and high surface work function via depositing Bi, Al, or Au metals on the surface of copper foil for in situ alloying with lithium is proposed. It is discovered that the electronic localization can induce self‐smoothing effect of Li ions, as a result, significantly suppressing the growth of dendritic lithium. Meanwhile, the high surface work function can effectively alleviate side reactions between the electrolyte and lithium. With the as‐obtained ultrathin alloys as anodes, excellent cycling performance is achieved. The half cells run stably after more than 120 cycles under high capacity of 4 mAh cm−2. The S||Bi/Cu‐Li full cell delivers a specific capacity of 736 mAh g−1 after 200 cycles. This work provides a new strategy for fabricating long‐life and high‐capacity lithium batteries.

A trade-off-free fluorosulfate-based flame-retardant electrolyte additive for high-energy lithium batteries

A synthetic additive bearing fluorosulfate moieties allows a high thermal stability for organocarbonate electrolyte in high-capacity lithium batteries without showing the performance trade-off behavior.

Reinforced concrete inspired Si/rGO/cPAN hybrid electrode: highly improved lithium storage via Si electrode nanoarchitecture engineering.

Electrode nanoarchitecture engineering is a transformative way to improve the structural stability and build robust transport charge pathways for high-capacity silicon in lithium ion batteries (LIBs). However, the violent expansion of silicon during the lithiation/delithiation process is the chief reason for its limited industrialization. Here, we fabricated an integrated electrode structure using polyacrylonitrile (PAN) and graphene oxide (GO) inspired by reinforced concrete. Based on low-temperature annealing, cyclized PAN was assembled on the surface of silicon nanoparticles and tightly combined with reduced graphene oxide (rGO), which could construct stable and efficient transport channels for electrons and lithium ions and address the issues of electrode structure and interface stability. The resultant Si/rGO/cPAN (RC-Si) as the LIB anode exhibits exceptional combined performances including extraordinary mechanical properties, excellent cycling stability (∼1150 mA h g-1 at 2 A g-1 over 500 cycles), superior rate capability (∼600 mA h g-1 at 12 A g-1), and high areal capacity (∼5.6 mA h cm-2 at 0.5 mA cm-2). The novel electrode design concept is promising to promote the practical application of silicon anodes and open a new avenue to develop other high-capacity anodes for high-performance batteries.

An Electrochemical-Mechanical Phase Field Model for Lithium Dendrite

Lithium metal is considered a holy grail anode material for high theoretical energy batteries. However, lithium dendrite associated with interface instability has severely derailed efforts to commercialize safe and high-capacity lithium batteries. Here, we propose an electrochemical-mechanical phase field model by incorporating the elastic energy into the Gibbs free energy to reveal the role of stress in lithium dendrites. It is found that the compressive stress associated with lithium electroplating gradually concentrates near the nucleation site, acting as a driving force for dendrite formation. The surface energy plays a critical role in determining the dendrite morphology, the higher the surface energy the higher the curvature of the dendrite. A phase diagram of four types of morphologies is identified in terms of the interface energy density and charging rate. Our analysis suggests that a low charging rate or improving the interfacial Li+ diffusion ability is beneficial to maintaining interface stability.

Functional separator with a lightweight carbon-coating for stable, high-capacity organic lithium batteries

• A C@PP separator is proposed to suppress the shuttle of quinone electrodes. • Inhibitory shuttle correlates with the physical barrier and excellent adsorption. • The separator increases the utilization of PT cathode for high capacities. • The other three quinone cathodes also exhibit greatly improved performances. A major challenge facing organic rechargeable batteries is the problem of the dissolution and shuttle effect of organic cathodes in aprotic electrolytes, resulting in limited capacity, low cyclability and poor rate performance. Herein, a functional polypropylene separator coated with Ketjen black (C@PP) was introduced to tackle the shuttle issue. The inhibitory effect on quinone shuttle correlates with physical barrier and excellent adsorption of Ketjen black (KB), as proved by a series of spectroscopy studies. With the C@PP separator, quinone cathodes including pentacene-5,7,12,14-tetrone (PT), Calix[4] quinone (C4Q), 9,10-anthraquinone (AQ) and 9,10-phenanthrenequinone (PQ) demonstrated high reversible capacity and excellent cyclic stability in Li storage. Specially, PT exhibited high capacity (>300 mAh g −1 ), long-term cyclability (~0.06% decay per cycle over 400 cycles at 0.5 C) and fast kinetic (5 C). C4Q delivered high energy density (782 Wh kg −1 ) and respectable cyclability (~60% after 500 cycles). This facile and versatile separator modifying strategy opens a new avenue for solving quinone electrode issues to achieve high-performance OLBs.

Isometric Thionated Naphthalene Diimides As Organic Cathodes for High Capacity Lithium Batteries

Although naphthalene diimide (NDI) and its derivatives have been widely used for organic Li-ion batteries (OLIBs), they are limited by a low lithium uptake capacity and ambiguous lithiation mechani...

(Invited) Tailored Design of Polymer Electrolytes for Advanced High-Capacity and High-Voltage Lithium Batteries

For decades, the use of polymer-based lithium battery electrolytes has been restricted to cells containing low-voltage positive electrodes such as LiFePO4, which intrinsically limited the achievable energy density. On the other hand, the employment of polymer electrolytes allowed for the use of lithium metal negative electrodes, even though the operation remained limited to elevated temperatures due to the relatively low ionic conductivity at room temperature.1,2 Accordingly, if these two challenges, i.e., the limited stability towards oxidation and the poor ionic conductivity, could be overcome, polymer-based electrolytes may pave the way towards high-energy lithium-metal batteries – one of the main targets of global battery research activities.3,4 Herein, we report our latest achievements in this field, specifically for single-ion conductors, as they additionally provide highly homogeneous lithium deposition and suppress the detrimental occurrence of reversed cell polarization upon cycling.2,5 These achievements include the design of polymer electrolytes with enhanced single-ion conductivities of about 10-3 S cm-1 at 30 °C as well as excellent stability towards lithium metal and high-energy next generation cathode materials like Li(Ni0.8Mn0.1Co0.1)O2 – up to anodic cut-off potentials as high as 4.5 V. As a result, these new single-ion conducting polymer electrolytes allow for highly stable cycling of such cells at 20 °C and even 0 °C.6,7 We hope that this work will trigger further research efforts also in other labs to boost the development of advanced lithium-polymer batteries. References J. Kalhoff, G. G. Eshetu, D. Bresser, and S. Passerini, ChemSusChem, 8, 2154–2175 (2015).D. T. Hallinan and N. P. Balsara, Annu. Rev. Mater. Res., 43, 503–525 (2013).X.-B. Cheng, R. Zhang, C.-Z. Zhao, and Q. Zhang, Chem. Rev., 117, 10403–10473 (2017).Y. Guo, H. Li, and T. Zhai, Adv. Mater., 29, 1700007 (2017).H. Zhang et al., Chem. Soc. Rev., 46, 797–815 (2017).H.-D. Nguyen et al., Energy Environ. Sci., 11, 3298–3309 (2018).Z. Chen et al., submitted manuscript.

Stable high-capacity and high-rate silicon-based lithium battery anodes upon two-dimensional covalent encapsulation

Silicon is a promising anode material for lithium-ion and post lithium-ion batteries but suffers from a large volume change upon lithiation and delithiation. The resulting instabilities of bulk and interfacial structures severely hamper performance and obstruct practical use. Stability improvements have been achieved, although at the expense of rate capability. Herein, a protocol is developed which we describe as two-dimensional covalent encapsulation. Two-dimensional, covalently bound silicon-carbon hybrids serve as proof-of-concept of a new material design. Their high reversibility, capacity and rate capability furnish a remarkable level of integrated performances when referred to weight, volume and area. Different from existing strategies, the two-dimensional covalent binding creates a robust and efficient contact between the silicon and electrically conductive media, enabling stable and fast electron, as well as ion, transport from and to silicon. As evidenced by interfacial morphology and chemical composition, this design profoundly changes the interface between silicon and the electrolyte, securing the as-created contact to persist upon cycling. Combined with a simple, facile and scalable manufacturing process, this study opens a new avenue to stabilize silicon without sacrificing other device parameters. The results hold great promise for both further rational improvement and mass production of advanced energy storage materials.

State-of-the-Art Research and Applications of Carbon Foam Composite Materials as Electrodes for High-Capacity Lithium Batteries

The development of advanced electrode materials for next-generation rechargeable lithium batteries with high specific capacity and energy density and long life is promising to meet the demand for e...

Field measurement of the dynamic responses of a suspended monorail train–bridge system

This work presents an integrated and large-scale field measurement of the dynamic responses of a suspended monorail train–bridge system, which is rarely reported. This experimental train uses a high-capacity lithium battery for the operation. The maximum running speed of the train is up to 60 km/h. The experimental line was constructed on a full-scale steel bridge composed of a straight section, curved sections with different horizontal radiuses and a slope section of 60‰. First, the train–bridge dynamic responses under different conditions are extracted based on the field test. Then, the car-body accelerations under different train speeds and bridge sections are analysed in detail, and the running stability of the vehicle is assessed by adopting the Sperling index. By comparing the dynamic responses of the train–straight bridge interaction and the train–curved bridge interaction, some significant discrepancies and interesting phenomena could be found. Subsequently, based on the test data, the vertical rotation angles of the beam end and the dynamic amplification factors of the bridge displacements under different vehicle speeds and bridge sections are obtained, and then the vibration levels of the bridge under different conditions are evaluated. Finally, by analysing the frequency spectra of the dynamic responses, the dominant frequencies of the acceleration signals of this monorail vehicle and bridge subsystems are revealed; in addition, the sensitive wavelengths that influence the running stability of the vehicle are found. These measurement results may provide valuable guidance for the design of the suspended monorail system and numerical model validation.

Impact of high-power charging on the durability and safety of lithium batteries used in long-range battery electric vehicles

Battery electric vehicles with a range of more than 500 km are expected to become increasingly competitive in the future. The energy density of the currently available lithium batteries should be significantly increased to support the operation of such vehicles, and high-power charging is required to reduce the charging time. However, high-power charging may negatively affect the durability and safety of lithium batteries because of increased heat generation, capacity fading, and lithium plating, which can induce the risk of battery thermal runaway. Currently, there are no established boundary conditions for high-power charging or methods for evaluating its risks, especially in case of high-capacity lithium batteries. This study proposes a test procedure for examining the reaction characteristics of the capacity fading and thermal tolerance of lithium batteries that are subjected to high-power charging. Further, the migration characteristics of the temperature threshold of battery thermal runaway are investigated using the proposed procedure. The test results demonstrate that high-power charging significantly impacts the durability and thermal safety of the high-capacity lithium batteries. In particular, the capacity fading rate can reach up to 30% only after 100 charge cycles depending on the battery type. Furthermore, the thermal tolerance can decrease up to 40% by considering the change in the self-heating temperature as an indicator. Based on the study results, it can be concluded that the thermal management systems should be carefully designed to satisfy the high-power charging requirements. Otherwise, the high power charging only can be performed with limited range for battery electric cars with long all electric range.

Structure design and mechanism analysis of silicon anode for lithium-ion batteries

Silicon-based material is one of the most promising substitutes of widely used graphite anodes for the next generation Li-ion batteries due to its high theoretical capacity, low working potential, environmental friendliness, and abundant natural resource. However, the huge volume expansion and serious interfacial side reactions during lithiation and delithiation progresses of the silicon anode are the key issues which impede their further practical applications. Rational designs of silicon nanostructures are effective ways to address these problems. In this progress report, we firstly highlight the fundamental scientific problems, and then focus on recent progresses in design, preparation, in - situ characterization methods and failure mechanism of nanostructured silicon anode for high capacity lithium battery. We also summarize the key lessons from the successes so far and offer perspectives and future challenges to promote the applications of silicon anode in practical lithium batteries.