Adding thermal conductivity enhancements to increase thermal power in solid-liquid phase-change thermal energy storage modules compromises volumetric energy density and often times reduces the mass and volume of active phase change material (PCM) by well over half. In this study, a new concept of building thermal energy storage modules using high-conductivity, solid-solid, shape memory alloys is demonstrated to eliminate this trade-off and enable devices that have both high heat transfer rate and high thermal capacity. Nickel titanium, Ni50.28Ti49.36, was solution heat treated and characterized using differential scanning calorimetry and Xenon Flash to determine transformation temperature (78deg-C), latent heat (183 kJm-3), and thermal conductivity in the Austenite and Martensite phases (12.92/12.64 Wm-1K-1). Four parallel-plate thermal energy storage demonstrators were designed, fabricated, and tested in a thermofluidic test setup. These included a baseline sensible heating module (aluminum), a conventional solid-liquid PCM module (aluminum/1-octadecanol), an all-solid-solid PCM module (Ni50.28Ti49.36), and a composite solid-solid/solid-liquid PCM module (Ni50.28Ti49.36/1-octadecanol). By using high-conductivity solid-solid PCMs, and eliminating the need for encapsulants and conductivity enhancements, we are able to demonstrate a 1.73-3.38 times improvement in volumetric thermal capacity and a 2.03-3.21 times improvement in power density as compared to the conventional approaches. These experimental results are bolstered by analytical models to explain the observed heat transfer physics and reveal a 5.86 times improvement in thermal time constant. This work demonstrates the ability to build high-capacity and high-power thermal energy storage modules using multifunctional shape memory alloys and opens the door for leap ahead improvement in thermal energy storage performance.
Balancing Thermodynamics, Kinetics, and Reversibility in Ti-Doped MgB2H8: A First-Principles Assessment of a Practical Solid-State Hydrogen Storage Material
New Technologies Research Center, University of West Bohemia（新技研究中心，西波希米亚大学）；Department of Physics, Bacha Khan University（巴哈汗大学物理系）
Building a physics-aware AI ecosystem for solid-state hydrogen storage materials
Tohoku University（东北大学）；National University of Singapore（新加坡国立大学）；University at Buffalo（布法罗纽约州立大学）；The University of Tokyo（东京大学）；Washington University in St. Louis（华盛顿大学圣路易斯分校）；Utrecht University（乌得勒支大学）；University of Turin（都灵大学）
Particle Morphology and Lithium Segregation to Surfaces of the Li$_7$La$_3$Zr$_2$O$_{12}$ Solid Electrolyte
用于固态锂离子电池的固体电解质激发了对下一代能量存储应用的极大兴趣。Li $_7$ La $_3$ Zr $_2$ O $_{12}$石榴石型固体电解质由于其高离子电导率而受到相当大的关注。然而，基于Li $_7$ La $_3$ Zr $_2$ O $_{12}$的固态器件的成功应用仍然存在若干挑战，例如枝晶形成和在许多Li嵌入/提取循环中保持界面处的物理接触。在这里，我们应用第一性原理密度泛函理论提供的见解，在各种物理和化学条件下的Li $_7$ La $_3$ Zr $_2$ O $_{12}$粒子形态。我们的研究结果表明，锂偏析的表面，建议富锂晶界在典型的合成和烧结条件。我们的研究结果的基础上，我们提出了切实可行的策略，以遏制Li $_7$ La $_3$ Zr $_2$ O $_{12}$接口的Li偏析。这种方法可以扩展到其他锂离子导体的实际储能装置的设计。
Enhanced electrocaloric and energy-storage properties of environment-friendly ferroelectric Ba0.9Sr0.1Ti1-xSnxO3 ceramics
研究了采用传统固相反应法制备的环境友好型Ba 0. 9 Sr 0. 1 Ti 1-xSnxO 3（BSTS-x）铁电陶瓷的电热效应和储能性能。在我们的样品中发现了超过80%的显著能源效率。特别地，BSTS-5和BSTS-10样品在室温（RT）附近的宽温度范围内分别表现出92%和88%的效率。直接EC测量和间接方法的基础上的热力学方法被用来表征EC效应，两者都得到了一致的结果。BSTS-0在368 K下获得了最大的电热响应率0.73 K mm/kV，在仅为7.4 kV/cm的低外加电场下绝热温度变化DT（EC）为0.55 K。随着Sn含量的增加，BSTS-x陶瓷的EC响应降低，而它们的扩散性在以RT为中心的广泛的温度范围内增加。研究结果表明，设计具有更高EC效应和能量效率的环境友好型材料用于潜在的固态制冷和储能装置是可能的。
Metallic solid-state hydrogen storage crystals achieved through chemical precompression under ambient conditions
Key Laboratory of Material Simulation Methods & Software of Ministry of Education, College of Physics, Jilin University（吉林大学物理学院教育部材料模拟方法与软件重点实验室）；Institute of Atomic and Molecular Physics, Jilin University（吉林大学原子与分子物理研究所）；Institute of Theoretical Chemistry, College of Chemistry, Jilin University（吉林大学化学学院理论化学研究所）
Dissipation losses limiting first-order phase transition materials in cryogenic caloric cooling: A case study on all-d-metal Ni(-Co)-Mn-Ti Heusler alloys
Ni-Mn基Heusler合金，特别是全d金属Ni（-Co）-Mn-Ti合金，在其磁结构马氏体相变过程中可以实现大的多热量效应，是一种非常有前途的节能固态制冷材料。然而，对于Ni（-Co）-Mn-Ti体系中至关重要的相变熵变$Δs_t$，目前还没有全面的研究。在这里，我们提出了一个系统的研究分析的组成和温度依赖性的$Δs_t$。我们的研究结果揭示了一个实质性的结构熵变贡献约65 J（千克K）$^{-1}$，这是在较低的温度下由一个越来越负的熵变与磁子系统相关联的补偿。这导致Ni $_{35}$ Co $_{15}$ Mn $_{50-y}$ Ti $_{y}$和Ni $_{33}$ Co $_{17}$ Mn $_{50-y}$ Ti $_{y}$中的补偿温度$T_{comp}$分别为75 K和300 K，低于该温度马氏体转变被阻止。此外，我们同时测量的磁，结构和电子子系统的温度和磁场诱导马氏体相变附近的$T_{comp}$，表现出异常增加的滞后，从而在低温下耗散能量的响应。同时测量的磁化强度和绝热温度变化$ΔT_{ad}$在脉冲磁场揭示了一个变化的符号$ΔT_{ad}$和一个实质性的积极的和不可逆的$ΔT_{ad}$高达15 K在15 K作为一个结果的耗散损耗增加和热容降低。最重要的是，这种现象是普遍的，它适用于任何一阶材料与不可忽略的滞后和任何刺激，有效地限制了利用其热效应的气…
University of Science and Technology Beijing（北京科技大学）；Nanjing University of Posts and Telecommunications（南京邮电大学）；Chinese Academy of Sciences（中国科学院）；Tsinghua University（清华大学）；Nanjing University of Aeronautics and Astronautics（南京航空航天大学）；Southern University of Science and Technology（南方科技大学）
High-Entropy Hydrides for Fast and Reversible Hydrogen Storage at Room Temperature: Binding-Energy Engineering via First-Principles Calculations and Experiments
