Increasing energy density of Li-ion batteries (LiBs) along with fast charging capability are two key approaches to eliminate range anxiety and boost mainstream adoption of electric vehicles (EVs). ...Either the increase of energy density or of charge rate, however, heightens the risk of lithium plating and thus deteriorates cell life. The trilemma of fast charging, energy density and cycle life are studied systematically in this work utilizing a physics-based aging model with incorporation of both lithium plating and solid-electrolyte-interphase (SEI) growth. The model is able to capture the key feature of temperature-dependent aging behavior of LiBs, or more specifically, the existence of an optimal temperature with the longest cycle life. We demonstrate that this optimal temperature is a result of competition between SEI growth and lithium plating. Further, it is revealed that either the increase of charge rate or of energy density accelerates lithium plating induced aging. As such, the optimal temperature for cell life increases from ∼20 °C for a high-power cell at 1C charge to ∼35–45 °C with the increase of charge rate and/or energy density. It would be beneficial to further increase the charge temperature in order to enable robust fast charging of high energy EV cells.
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•Temperature-dependent aging behavior of Li-ion battery is studied numerically.•Overall aging rate depends on the competition of lithium plating and SEI growth.•The optimal temperature for cycle life increases with charge rate & energy density.•Raising charging temperature is an effective method to eliminating lithium plating.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The rapid spread of new coronaviruses throughout China and the world in 2019-2020 has had a great impact on China's economic and social development. As the backbone of Chinese society, Chinese ...universities have made significant contributions to emergency risk management. Such contributions have been made primarily in the following areas: alumni resource collection, medical rescue and emergency management, mental health maintenance, control of staff mobility, and innovation in online education models. Through the support of these methods, Chinese universities have played a positive role in the prevention and control of the epidemic situation. However, they also face the problems of alumni's economic development difficulties, the risk of deadly infection to medical rescue teams and health workers, infection of teachers and students, and the unsatisfactory application of information technology in resolving the crisis. In response to these risks and emergency problems, we propose some corresponding solutions for public dissemination, including issues related to medical security, emergency research, professional assistance, positive communication, and hierarchical information-based teaching.
Fast charging is a key enabler of mainstream adoption of electric vehicles (EVs). None of today’s EVs can withstand fast charging in cold or even cool temperatures due to the risk of lithium plating. ...Efforts to enable fast charging are hampered by the trade-off nature of a lithium-ion battery: Improving low-temperature fast charging capability usually comes with sacrificing cell durability. Here, we present a controllable cell structure to break this trade-off and enable lithium plating-free (LPF) fast charging. Further, the LPF cell gives rise to a unified charging practice independent of ambient temperature, offering a platform for the development of battery materials without temperature restrictions. We demonstrate a 9.5 Ah 170 Wh/kg LPF cell that can be charged to 80% state of charge in 15 min even at −50 °C (beyond cell operation limit). Further, the LPF cell sustains 4,500 cycles of 3.5-C charging in 0 °C with <20% capacity loss, which is a 90× boost of life compared with a baseline conventional cell, and equivalent to >12 y and >280,000 miles of EV lifetime under this extreme usage condition, i.e., 3.5-C or 15-min fast charging at freezing temperatures.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
A physics-based Li-ion battery (LIB) aging model accounting for both lithium plating and solid electrolyte interphase (SEI) growth is presented, and is applied to study the aging behavior of a cell ...undergoing prolonged cycling at moderate operating conditions. Cell aging is found to be linear in the early stage of cycling but highly nonlinear in the end with rapid capacity drop and resistance rise. The linear aging stage is found to be dominated by SEI growth, while the transition from linear to nonlinear aging is attributed to the sharp rise of lithium plating rate. Lithium plating starts to occur in a narrow portion of the anode near the separator after a certain number of cycles. The onset of lithium plating is attributed to the drop of anode porosity associated with SEI growth, which aggravates the local electrolyte potential gradient in the anode. The presence of lithium metal accelerates the porosity reduction, further promoting lithium plating. This positive feedback leads to exponential increase of lithium plating rate in the late stage of cycling, as well as local pore clogging near the anode/separator interface which in turn leads to a sharp resistance rise.
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•We present a Li-ion battery model capable of predicting Li plating induced aging.•The model is able to capture the transition from linear to nonlinear aging.•Nonlinear aging is attributed to exponential increase of Li plating rate.•Anode porosity drop due to SEI growth is response for onset of Li plating.•There is positive feedback btw porosity drop and Li plating rate increase.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Adding a 200-mile range in 10 min, so-called extreme fast charging (XFC), is the key to mainstream adoption of battery electric vehicles (BEVs). Here, we present an asymmetric temperature modulation ...(ATM) method that, on one hand, charges a Li-ion cell at an elevated temperature of 60°C to eliminate Li plating and, on the other, limits the exposure time at 60°C to only ∼10 min per cycle, or 0.1% of the lifetime of a BEV, to prevent severe solid-electrolyte-interphase growth. The asymmetric temperature between charge and discharge opens a new path to enhance kinetics and transport during charging while still achieving long life. We show that a 9.5-Ah 170-Wh/kg cell sustained 1,700 XFC cycles (6 C charge to 80% state of charge) at 20% capacity loss with the ATM, compared to 60 cycles for a control cell, and that a 209-Wh/kg BEV cell retained 91.7% capacity after 2,500 XFC cycles.
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•Asymmetric charge and discharge temperatures enable durable extreme fast charging•High-temperature charging eliminates Li plating by enhanced transport and kinetics•Limited exposure time to high temperature avoids severe SEI growth•Elevated charging temperature reduces battery cooling need by >12×
Electric vehicles will only be truly competitive when they can be charged as fast as refilling a gas tank. The US Department of Energy has set a goal of developing extreme fast charging (XFC) technology that can add 200 miles of driving range in 10 min. A critical barrier to XFC is Li plating, which usually occurs at high charge rates and drastically deteriorates battery life and safety. Here, we present an asymmetric temperature modulation (ATM) method that charges a Li-ion cell at an elevated temperature of 60°C to eliminate Li plating and limits the exposure time to 60°C to only ∼10 min per cycle to prevent serious materials degradation. Using industrially available battery materials, we show that a high-energy (209 Wh/kg) Li-ion cell with the ATM method retains 91.7% capacity after 2,500 XFC cycles (equal to 500,000 miles of driving range), far exceeding the US Department of Energy (DOE) target (500 cycles at 20% loss).
An asymmetric temperature modulation method is presented in which a Li-ion cell is rapidly pre-heated to and charged at ∼60°C, and the cell’s exposure time to 60°C is limited to ∼10 min per cycle. The elevated temperature enhances kinetics and transport and hence eliminates Li plating; the limited exposure time to 60°C avoids severe materials degradation. We demonstrate that a high energy (209 Wh/kg) cell retains 91.7% capacity after 2,500 cycles of 10-min extreme fast charging, far exceeding the DOE target.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Wadsley–Roth phased niobates are promising anode materials for lithium‐ion batteries, while their inherently low electrical conductivity still limits their rate‐capability. Herein, a novel doped ...Mo1.5W1.5Nb14O44 (MWNO) material is facilely prepared via an ionothermal‐synthesis‐assisted doping strategy. The detailed crystal structure of MWNO is characterized by neutron powder diffraction and aberration corrected scanning transmission electron microscope, unveiling the full occupation of Mo6+‐dopant at the t1 tetrahedral site. In half‐cells, MWNO exhibits enhanced fast‐rechargeability. The origin of the improved performance is investigated by ultraviolet–visible diffuse reflectance spectroscopy, density functional theory (DFT) computation, and electrochemical impedance spectroscopy, revealing that bandgap narrowing improves the electrical conductivity of MWNO. Furthermore, operando X‐ray diffraction elucidates that MWNO exhibits a typical solid‐solution phase conversion‐based lithium‐ion insertion/extraction mechanism with reversible structural evolution during the electrochemical reaction. The boosted lithium‐ion diffusivity of MWNO, due to the Mo6+/W6+ doping effect, is confirmed by a galvanostatic intermittent titration technique and DFT. With the simultaneously enhanced electrical conductivity and lithium‐ion diffusivity, MWNO successfully demonstrates its fast‐rechargeability and practicality in the LiNi0.5Mn1.5O4‐coupled full‐cells. Therefore, this work illustrates the potential of ionothermal synthesis in energy storage materials and provides a mechanistic understanding of the doping effect on improving material's electrochemical performance.
A new high‐performance nanoporous Mo1.5W1.5Nb14O44 lithium‐ion battery anode material is facilely prepared by a novel ionothermal‐synthesis‐assisted doping strategy, which concurrently enables the improvement of lithium‐ion diffusivity via a doping effect and a templating effect of the ionic liquid together with the enhancement of electrical conductivity via doping‐induced cation redistribution and bandgap narrowing. Therefore, the obtained Mo1.5W1.5Nb14O44 exhibits superb fast‐rechargeability in half‐cells and full‐cells.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Objective： This review focuses on the current knowledge on the implication and significance of beta 2 microglobulin （β2M）, a conservative immune molecule in vertebrate.Data Sources： The data used in ...this review were obtained from PubMed up to October 2015.Terms of β2M, immune response, and infection were used in the search.Study Selections： Articles related to β2M were retrieved and reviewed.Articles focusing on the characteristic and function of β2M were selected.The exclusion criteria of articles were that the studies on β2M-related molecules.Results： β2M is critical for the immune surveillance and modulation in vertebrate animals.The dysregulation of β2M is associated with multiple diseases, including endogenous and infectious diseases.β2M could directly participate in the development of cancer cells, and the level of β2M is deemed as a prognostic marker for several malignancies.It also involves in forming major histocompatibility complex （MHC class Ⅰ or MHC Ⅰ） or like heterodimers, covering from antigen presentation to immune homeostasis.Conclusions： Based on the characteristic of β2M, it or its signaling pathway has been targeted as biomedical or therapeutic tools.Moreover, β2M is highly conserved among different species, and overall structures are virtually identical, implying the versatility of β2M on applications.
Intracellular tau accumulation forming neurofibrillary tangles is hallmark pathology of Alzheimer's disease (AD), but how tau accumulation induces synapse impairment is elusive. By overexpressing ...human full‐length wild‐type tau (termed hTau) to mimic tau abnormality as seen in the brain of sporadic AD patients, we find that hTau accumulation activates JAK2 to phosphorylate STAT1 (signal transducer and activator of transcription 1) at Tyr701 leading to STAT1 dimerization, nuclear translocation, and its activation. STAT1 activation suppresses expression of N‐methyl‐D‐aspartate receptors (NMDARs) through direct binding to the specific GAS element of GluN1, GluN2A, and GluN2B promoters, while knockdown of STAT1 by AAV‐Cre in STAT1flox/flox mice or expressing dominant negative Y701F‐STAT1 efficiently rescues hTau‐induced suppression of NMDAR expression with amelioration of synaptic functions and memory performance. These findings indicate that hTau accumulation impairs synaptic plasticity through JAK2/STAT1‐induced suppression of NMDAR expression, revealing a novel mechanism for hTau‐associated synapse and memory deficits.
Synopsis
Tau accumulation, one hallmark of Alzheimer's disease, induces synaptic impairment by activating JAK2/STAT1 signaling, which transcriptionally suppresses N‐methyl‐D‐aspartate receptors. Downregulation of STAT1 ameliorates synaptic function and memory performance in mice.
Accumulation of hTau triggers JAK2‐dependent STAT1 dimerization, activation and nuclear translocation.
STAT1 activation directly suppresses N‐methyl‐D‐aspartate receptor expression.
Downregulation of STAT1 rescues hTau‐induced N‐methyl‐D‐aspartate receptor suppression.
Tau accumulation, one hallmark of Alzheimer's disease, induces synaptic impairment by activating JAK2/STAT1 signaling, which transcriptionally suppresses N‐methyl‐D‐aspartate receptors. Downregulation of STAT1 ameliorates synaptic function and memory performance in mice.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Voltage plateau during relaxation or discharge after charging is a distinct signal associated with stripping of deposited Li metal and hence a feasible tool for online detection of Li plating in ...Li-ion batteries. Here, we present a physics-based model with incorporation of Li plating and stripping to gain a fundamental understanding of the voltage plateau behavior. Specifically, we focus on the internal cell characteristics when voltage plateau occurs and on key factors affecting the shape and duration of voltage plateau. Furthermore, the validity of using the duration of voltage plateau for estimating Li plating amount is assessed. It is found that the duration of voltage plateau depends on the rate of Li stripping, while the stripping rate is restricted by the capability of Li+ intercalation into graphite. Parameters like intercalation kinetics, solid-state diffusivity of graphite and cell temperature can substantially influence the voltage curves even with the same amount of Li plating. Further, we report an interesting phenomenon that during Li stripping one part of anode near the separator has net oxidation current (local stripping rate > intercalation rate), providing Li+ ions and electrons to the other part of anode near the foil which has net reduction current.
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•We present a Li-ion battery model incorporating both Li plating and stripping.•Voltage plateau after charging due to by Li stripping is captured and analyzed.•Length of voltage plateau depends highly on capability of graphite intercalation.•Anode splits into to two parts during Li stripping.•Differential voltage approach to quantify Li plating amount is assessed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Lithium-ion batteries with nickel-rich layered oxide cathodes and graphite anodes have reached specific energies of 250-300 Wh kg
(refs.
), and it is now possible to build a 90 kWh electric vehicle ...(EV) pack with a 300-mile cruise range. Unfortunately, using such massive batteries to alleviate range anxiety is ineffective for mainstream EV adoption owing to the limited raw resource supply and prohibitively high cost. Ten-minute fast charging enables downsizing of EV batteries for both affordability and sustainability, without causing range anxiety. However, fast charging of energy-dense batteries (more than 250 Wh kg
or higher than 4 mAh cm
) remains a great challenge
. Here we combine a material-agnostic approach based on asymmetric temperature modulation with a thermally stable dual-salt electrolyte to achieve charging of a 265 Wh kg
battery to 75% (or 70%) state of charge in 12 (or 11) minutes for more than 900 (or 2,000) cycles. This is equivalent to a half million mile range in which every charge is a fast charge. Further, we build a digital twin of such a battery pack to assess its cooling and safety and demonstrate that thermally modulated 4C charging only requires air convection. This offers a compact and intrinsically safe route to cell-to-pack development. The rapid thermal modulation method to yield highly active electrochemical interfaces only during fast charging has important potential to realize both stability and fast charging of next-generation materials, including anodes like silicon and lithium metal.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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