《科学》（20240913出版）一周论文导读
编译|未玖
Science, 13 SEP 2024, VOL 385, ISSUE 6714
《科学》2024年9月13日，第385卷，6714期
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材料科学Materials Science
Stoichiometric reconstruction of the Al2O3(0001) surface
Al2O3（0001）表面的化学计量重构
▲ 作者：JOHANNA I. HüTNER, ANDREA CONTI, DAVID KUGLER, FLORIAN MITTENDORFER, GEORG KRESSE, MICHAEL SCHMID, ET AL.
▲链接：
https://www.science.org/doi/10.1126/science.adq4744
▲摘要：
材料的宏观特性源于基本的原子尺度细节，但对于绝缘体来说，解析表面结构仍是一个挑战。
研究组使用具有原子定义尖端的非接触原子力显微镜对α-氧化铝（α-Al2O3）的（0001）基面进行了成像。表面形成了一个复杂的（√31 × √31）R±9°重构。单个氧和铝表面原子的横向位置直接源自实验；研究组通过计算模型确定了其与底层晶体块的连接方式。
在重构之前，表面Al原子呈不利的三重平面配位；重构实现了与亚表面O的再杂化，从而获得极大能量增益。重构表面仍保持Al2O3的化学计量比。
▲ Abstract：
Macroscopic properties of materials stem from fundamental atomic-scale details, yet for insulators, resolving surface structures remains a challenge. We imaged the basal (0001) plane of α–aluminum oxide (α-Al2O3) using noncontact atomic force microscopy with an atomically defined tip apex. The surface formed a complex (√31 × √31)R±9° reconstruction. The lateral positions of the individual oxygen and aluminum surface atoms come directly from experiment; we determined with computational modeling how these connect to the underlying crystal bulk. Before the restructuring, the surface Al atoms assume an unfavorable, threefold planar coordination; the reconstruction allows a rehybridization with subsurface O that leads to a substantial energy gain. The reconstructed surface remains stoichiometric, Al2O3.
能源科学Energy Science
Solvent-mediated oxide hydrogenation in layered cathodes
层状阴极中溶剂介导的氧化物氢化
▲ 作者：GANG WAN, TRAVIS P. POLLARD, LIN MA, MARSHALL A. SCHROEDER, CHIA-CHIN CHEN, ZIHUA ZHU, ET AL.
▲链接：
https://www.science.org/doi/10.1126/science.adg4687
▲摘要：
自放电和化学诱导的机械效应降低了嵌入式电致变色和电化学储能装置的日历寿命和循环寿命。在可充电锂离子电池中，阴极的自放电会随着时间的推移导致电压和容量损失。主流自放电模型聚焦于锂离子从电解液扩散至阴极的过程。
研究组展示了另一种途径，其中层状过渡金属氧化物阴极的氢化通过氢从碳酸盐溶剂转移到脱锂氧化物诱导自放电。在自放电阴极中，他们进一步观察到质子和锂离子浓度梯度负相关，这有助于脱锂阴极中化学和结构的异质性，从而加速降解。
在脱锂阴极中发生的氢化会影响层状阴极的化学-机械耦合以及锂离子电池的日历寿命。
▲ Abstract：
Self-discharge and chemically induced mechanical effects degrade calendar and cycle life in intercalation-based electrochromic and electrochemical energy storage devices. In rechargeable lithium-ion batteries, self-discharge in cathodes causes voltage and capacity loss over time. The prevailing self-discharge model centers on the diffusion of lithium ions from the electrolyte into the cathode. We demonstrate an alternative pathway, where hydrogenation of layered transition metal oxide cathodes induces self-discharge through hydrogen transfer from carbonate solvents to delithiated oxides. In self-discharged cathodes, we further observe opposing proton and lithium ion concentration gradients, which contribute to chemical and structural heterogeneities within delithiated cathodes, accelerating degradation. Hydrogenation occurring in delithiated cathodes may affect the chemo-mechanical coupling of layered cathodes as well as the calendar life of lithium-ion batteries.
人工智能Artificial Intelligence
Durably reducing conspiracy beliefs through dialogues with AI
通过与AI的对话持续减少阴谋论
▲ 作者：THOMAS H. COSTELLO, GORDON PENNYCOOK AND DAVID G. RAND
▲链接：
https://www.science.org/doi/10.1126/science.adq1814
▲摘要：
