Nature, November 2022, Volume 611 Issue 7936
《自然》, 2022年11月，第611卷7639期
化学
Chemistry
Fast charging of energy-dense lithium-ion batteries
能量密集型锂离子电池的快速充电
▲ 作者：Chao-Yang Wang, Teng Liu, Xiao-Guang Yang, Shanhai Ge, Nathaniel V. Stanley, Eric S. Rountree, Yongjun Leng & Brian D. McCarthy
▲ 链接：
https://www.nature.com/articles/s41586-022-05281-0
▲ 摘要：
具有富镍层状氧化物阴极和石墨阳极的锂离子电池的比能量已经达到250-300 Wh kg -1，现在有可能制造出90千瓦时、具有300英里的巡航里程的电动汽车（EV）包。然而，由于有限的原始资源供应和过高的成本，使用这样的电池来缓解里程焦虑并不适用于主流电动汽车。10分钟快速充电可以缩小电动汽车电池的负担能力和可持续性，而不会引起里程焦虑。然而，能量密集电池（超过250 Wh kg -1或高于4 mAh cm -2）的快速充电仍然是一个巨大的挑战。
作者将基于非对称温度调制的材料不可知方法与热稳定的双盐电解质相结合，以实现在12（或11）分钟内将265 Wh kg -1电池充电到75%（或70%）状态，循环超过900（至2000）次。这相当于50万英里的里程，每次充电都是快速充电。此外，作者构建了一个电池组数字孪生子，以评估其冷却和安全性，并证明热调制4C充电只需要空气对流。这为电池包开发提供了一种紧凑且本质安全的途径。仅在快速充电过程中产生高活性电化学界面的快速热调制方法，对于实现下一代材料（包括硅和金属锂等阳极）的稳定和快速充电具有重要的潜力。
▲ Abstract：
Lithium-ion batteries with nickel-rich layered oxide cathodes and graphite anodes have reached specific energies of 250–300 Wh kg -1, 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 -1 or higher than 4 mAh cm -2) 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 -1 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.
Intrinsic glassy-metallic transport in an amorphous coordination polymer
非晶配位聚合物中玻璃-金属的固有输运
▲ 作者：Jiaze Xie, Simon Ewing, Jan-Niklas Boyn, Alexander S. Filatov, Baorui Cheng, Tengzhou Ma, Garrett L. Grocke, Norman Zhao, Ram Itani, Xiaotong Sun, Himchan Cho, Zhihengyu Chen, Karena W. Chapman, Shrayesh N. Patel, Dmitri V. Talapin, Jiwoong Park, David A. Mazziotti & John S. Anderson
▲ 链接：
https://www.nature.com/articles/s41586-022-05261-4
▲ 摘要：
导电有机材料，如掺杂有机聚合物、分子导体和新兴配位聚合物，支撑着从显示到柔性电子等各种技术。要实现传统绝缘有机材料的高导电性，就必须通过化学掺杂来调整其电子结构。即使是本质上导电的有机材料，如单组分分子导体，也需要结晶性来实现金属行为。
然而，导电聚合物通常是无定形的，以实现耐久性和可加工性。利用分子设计在未掺杂的非晶态材料中产生高导电性，将在许多应用中实现可调谐的和稳定的导电性，但没有本质导电的有机材料在无序时仍能保持高导电性。
研究报道了一种非晶配位聚合物，四硫代硫硫酸镍，具有显著的高电子导电性（达1200 S cm -1）和内在的玻璃-金属行为。
理论表明，这些特性是由分子重叠所实现的，分子重叠对结构扰动具有鲁棒性。这一系列不同寻常的特性导致了高导电性，在潮湿空气中稳定数周，pH值0-14和温度高达140℃。
这些发现表明，即使在严重无序的材料中，分子设计也可以使金属导电，提出了金属传输如何在没有周期结构的情况下存在的基本问题，并指出了这些材料令人兴奋的新应用。
▲ Abstract：
Conducting organic materials, such as doped organic polymers1, molecular conductors and emerging coordination polymers, underpin technologies ranging from displays to flexible electronics. Realizing high electrical conductivity in traditionally insulating organic materials necessitates tuning their electronic structure through chemical doping. Furthermore, even organic materials that are intrinsically conductive, such as single-component molecular conductors, require crystallinity for metallic behaviour. However, conducting polymers are often amorphous to aid durability and processability. Using molecular design to produce high conductivity in undoped amorphous materials would enable tunable and robust conductivity in many applications, but there are no intrinsically conducting organic materials that maintain high conductivity when disordered. Here we report an amorphous coordination polymer, Ni tetrathiafulvalene tetrathiolate, which displays markedly high electronic conductivity (up to 1,200 Scm -1) and intrinsic glassy-metallic behaviour. Theory shows that these properties are enabled by molecular overlap that is robust to structural perturbations. This unusual set of features results in high conductivity that is stable to humid air for weeks, pH 0–14 and temperatures up to 140°C. These findings demonstrate that molecular design can enable metallic conductivity even in heavily disordered materials, raising fundamental questions about how metallic transport can exist without periodic structure and indicating exciting new applications for these materials.
地质与地球物理学
Geology & Geophysics
Nd isotope variation between the Earth–Moon system and enstatite chondrites
地月系顽辉石球粒陨石之间的Nd同位素变化
▲ 作者：Shelby Johnston, Alan Brandon, Claire McLeod, Kai Rankenburg, Harry Becker & Peter Copeland
▲ 链接：
https://www.nature.com/articles/s41586-022-05265-0
▲ 摘要：
重新建构组成地球和月球的成分，对于了解它们的形成和组成演化至关重要。钕（Nd）同位素可通过指纹识别核合成成分来识别这些构建单元。研究表明，地球和月球的Sm/Nd比球粒陨石的平均值高出约2.4±0.5%，地球前体物质的初始142 /144Nd比值，较之前提出的更类似于麻辉石球粒陨石。
地球与球粒陨石Sm/Nd比值的差异可能反映了原行星盘内部混合作用的矿物分布。这一观测结果将月球的分化简化为月球岩浆海洋从形成到凝固的单一阶段。这也表明，在形成月球的大撞击中，构成地球和月球的物质之间没有发生Sm/Nd分馏。
▲ Abstract：
Reconstructing the building blocks that made Earth and the Moon is critical to constrain their formation and compositional evolution to the present. Neodymium (Nd) isotopes identify these building blocks by fingerprinting nucleosynthetic components. Here we show that Earth and the Moon instead had a Sm/Nd ratio approximately 2.4?±?0.5?per cent higher than the average for chondrites and that the initial 142Nd/144Nd ratio of Earth’s precursor materials is more similar to that of enstatite chondrites than previously proposed. The difference in the Sm/Nd ratio between Earth and chondrites probably reflects the mineralogical distribution owing to mixing processes within the inner protoplanetary disk. This observation simplifies lunar differentiation to a single stage from formation to solidification of a lunar magma ocean. This also indicates that no Sm/Nd fractionation occurred between the materials that made Earth and the Moon in the Moon-forming giant impact.
Ocean currents show global intensification of weak tropical cyclones
洋流显示弱热带气旋的全球强化
▲ 作者：Guihua Wang, Lingwei Wu, Wei Mei & Shang-Ping Xie
▲ 链接：
https://www.nature.com/articles/s41586-022-05326-4
▲ 摘要：
弱热带气旋占热带气旋的70%，但新研究发现，在过去30年里，所有海盆的弱热带气旋由于海洋暖化都有所增强。热带气旋登陆时会给沿海社区造成灾难，为了应对其可能影响，就要理解其行为。
理论和数学模型一致发现，热带气旋会随海表温度升高而增强，但由于缺乏足够准确的卫星观测证据，这个结论一直存在争议。基于卫星的传统证据可能会受到暴雨、云层、破碎波和飞沫的污染。
根据目前对全球变暖的预测，热带气旋如飓风和台风，预计会随着气温的升高而加剧。然而，尚不清楚历史记录是否已经显示出这一趋势的迹象，因为这些风暴通常形成于远离陆地的海洋区域，在那里直接测量表面风速很危险，因此并不现实。
研究者利用一组独特的洋流观测数据（由名为表面漂浮器的漂浮装置测得的高质量洋流数据）作为传统方式的补充，以全新方式量化了热带气旋的强度。热带气旋与洋流密切相关，研究分析显示，弱热带气旋，分为热带风暴和1级热带气旋，由于全球变暖在1991年到2020年期间有所增强。
研究者表示，相关结果可作为基线值，用来评估热带气旋模型的模拟和预测结果，帮助提高预测的准确度。
▲ Abstract：
Theory and numerical modelling suggest that tropical cyclones (TCs) will strengthen with rising ocean temperatures. Even though models have reached broad agreement on projected TC intensification, observed trends in TC intensity remain inconclusive and under active debate in all ocean basins except the North Atlantic, where aircraft reconnaissance data greatly reduce uncertainties. The conventional satellite-based estimates are not accurate enough to ascertain the trend in TC intensity, suffering from contamination by heavy rain, clouds, breaking waves and spray. Here we show that weak TCs (that is, tropical storms to category-1 TCs based on the Saffir–Simpson scale) have intensified in all ocean basins during the period 1991–2020, based on huge amounts of highly accurate ocean current data derived from surface drifters. These drifters have submerged ‘holy sock’ drogues at 15 m depth to reduce biases induced by processes at the air–sea interface and thereby accurately measure near-surface currents, even under the most destructive TCs. The ocean current speeds show a robust upward trend of ~4.0 cm s -1 per decade globally, corresponding to a positive trend of 1.8 m s -1 per decade in the TC intensity. Our analysis further indicates that globally TCs have strengthened across the entirety of the intensity distribution. These results serve as a historical baseline that is crucial for assessing model physics, simulations and projections given the failure of state-of-the-art climate models in fully replicating these trends.
机器学习和信息通信
machine learning & Information communication
Using machine learning to assess the livelihood impact of electricity access
使用机器学习评估电力接入对生计的影响
▲ 作者：Nathan Ratledge, Gabe Cadamuro, Brandon de la Cuesta, Matthieu Stigler & Marshall Burke
▲ 链接：
https://www.nature.com/articles/s41586-022-05322-8
▲ 摘要：
在世界许多地区，关于关键经济成果的数据稀少，阻碍了公共政策的制定、确定目标和评价。作者演示了卫星图像和机器学习的进步如何帮助改善这些数据和推理挑战。
在乌干达电网扩张的背景下，他们展示了如何结合卫星图像和计算机视觉来开发适合推断电力接入对生计的因果影响的地方生计测量方法。然后，研究者展示了基于机器学习的推理技术如何在应用于这些数据时，比传统方法提供更可靠的电气化因果影响估计。
他们估计，电网接入提高了乌干达农村村庄一级的资产财富，最高可达0.15个标准差。在研究期间，相对于未接受电网接入的地区，资产财富增长率增加了一倍多。
作者表示，该研究结果为基于网格的基础设施投资的影响提供了国家尺度的证据，该方法为数据稀疏环境下的未来政策评估提供了一种低成本、可推广的方法。
▲ Abstract：
In many regions of the world, sparse data on key economic outcomes inhibit the development, targeting and evaluation of public policy. We demonstrate how advancements in satellite imagery and machine learning (ML) can help ameliorate these data and inference challenges. In the context of an expansion of the electrical grid across Uganda, we show how a combination of satellite imagery and computer vision can be used to develop local-level livelihood measurements appropriate for inferring the causal impact of electricity access on livelihoods. We then show how ML-based inference techniques deliver more reliable estimates of the causal impact of electrification than traditional alternatives when applied to these data. We estimate that grid access improves village-level asset wealth in rural Uganda by up to 0.15 standard deviations, more than doubling the growth rate during our study period relative to untreated areas. Our results provide country-scale evidence on the impact of grid-based infrastructure investment and our methods provide a low-cost, generalizable approach to future policy evaluation in data-sparse environments.
A hybrid optical–wireless network for decimetre-level terrestrial positioning
用于分米地面定位的光-无线混合网络
▲ 作者：Jeroen C. J. Koelemeij, Han Dun, Cherif E. V. Diouf, Erik F. Dierikx, Gerard J. M. Janssen & Christian C. J. M. Tiberius
▲ 链接：
https://www.nature.com/articles/s41586-022-05315-7
▲ 摘要：
全球卫星导航系统（GNSS）被广泛用于导航和时间分配，这些功能对于移动通信网络等关键基础设施以及自动驾驶和可持续能源电网等新兴技术不可或缺。
尽管GNSS可以提供厘米级的精度，但由于多路径传播和天空的遮挡，GNSS接收器容易出现数米的误差，尤其是在最需要精确定位的城市地区。此外，全球导航卫星系统的脆弱性，加上缺乏备份系统，对依赖全球导航卫星系统的技术构成了严重的风险。
作者演示了一个独立于GNSS的地面定位系统，通过一个无线发射机群提供卓越的性能，通过光纤以太网网络在亚纳秒级别进行连接和时间同步。
使用与移动通信网络中遇到的类似的光学和无线传输方案，并利用频谱效率高的虚拟宽带信号，可以减轻多径传播的不利影响，从而在容易出现多径的户外环境中实现可靠的分米级定位和亚纳秒计时。
这项工作提供了一个未来的一瞥，电信网络不仅提供连接，而且以前所未有的准确性和可靠性提供独立于GNSS的授时和定位服务。
▲ Abstract：
Global navigation satellite systems (GNSS) are widely used for navigation and time distribution, features that are indispensable for critical infrastructure such as mobile communication networks, as well as emerging technologies such as automated driving and sustainable energy grids. Although GNSS can provide centimetre-level precision, GNSS receivers are prone to many-metre errors owing to multipath propagation and an obstructed view of the sky, which occur particularly in urban areas where accurate positioning is most needed. Moreover, the vulnerabilities of GNSS, combined with the lack of a back-up system, pose a severe risk to GNSS-dependent technologies. Here we demonstrate a terrestrial positioning system that is independent of GNSS and offers superior performance through a constellation of radio transmitters, connected and time-synchronized at the subnanosecond level through a fibre-optic Ethernet network. Using optical and wireless transmission schemes similar to those encountered in mobile communication networks, and exploiting spectrally efficient virtual wideband signals, the detrimental effects of multipath propagation are mitigated, thus enabling robust decimetre-level positioning and subnanosecond timing in a multipath-prone outdoor environment. This work provides a glimpse of a future in which telecommunication networks provide not only connectivity but also GNSS-independent timing and positioning services with unprecedented accuracy and reliability.
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