Articles techniques et présentations

为满足电动汽车对长续航和快充电的需求，提升锂离子电池的能量密度和快充性能至关重要。锂离子电池在快速充放电过程中的电极结构退化问题已成为制约其性能提升的关键瓶颈。尤其在高倍率循环条件下，电极活性颗粒内部会因锂离子浓度梯度和相变引发的非均匀体积膨胀而产生显著的机械应力，进而导致微裂纹的萌生与扩展。本研究建立了耦合锂离子扩散、相变、应力演化及断裂过程的COMSOL模型，系统研究了单晶电极颗粒、二级电极颗粒和厚电极的断裂行为。在单晶颗粒尺度，建立了耦合锂扩散、相变、应力与断裂的相场模型。研究发现脱锂路径具有取向依赖性，导致非均匀相变与晶格失配应力 ... En savoir plus

Vanadium redox flow batteries (VRBs) are a promising new energy storage technology designed for use in long term applications such as uninterruptible power supply and coupling with renewable energy sources (i.e. wind and solar). Crossover is the undesired transport of vanadium ions ... En savoir plus

With the Creation, roll-out, and maintenance of COMSOL Simulation apps, the role of simulation engineers and departments is expanding to include responsibilities similar to those of software developers. Within our department, we have undergone this transformation and will share the key ... En savoir plus

Freeze-dried (lyophilized) drug products offer extended shelf life and improved drug stability within a range of combination products including autoinjectors and pre-filled syringes. A key step in the use of combination products is the reconstitution of the freeze-dried drug product (DP) ... En savoir plus

As the global use of COMSOL® apps continues to grow, many developers are seeking practical and secure methods to protect their applications and control their usage. While traditional paid software often relies on license keys, there has been a lack of simple and flexible tools tailored ... En savoir plus

Vibration-based Piezoelectric Energy harvesters convert ambient vibration energy into an applicable electrical charge for wireless sensors, IoT applications, and charging the battery, which is most important to range improvement of the Electric Vehicle. This study analyses different ... En savoir plus

在所有电池系统中，锂氧电池的理论比能量最高，而实际比能量却明显不足。阻碍氧和/或电子传递导致多孔空气电极的有限利用，而实现对电化学和质量传递耦合的定量理解是具有挑战性的。本文首创了一种具有高度一致和可控通道单元的多孔电极，该电极排除了无序孔隙的随机性，从而能够研究控制机制。通过comsol建立了一个动态非均质模型，提供了LiO2的第一个时空分布，揭示了其在有限电子输运下的反向扩散轨迹。实验和模型的协同结合确定了通道尺寸在分为质量，杂交和电子传递控制的机制中的关键作用。对于大孔隙来说，提高Li2O2的导电性和减轻固液界面损伤比增强氧的扩散更为迫切 ... En savoir plus

The COMSOL Application Builder can tie a custom user interface to application-specific Java code. This functionality can be used to automatically coordinate changing model characteristics across multiple model nodes. A simple user interface can therefore allow simultaneous ... En savoir plus

The temperature distributions inside two packs (in-line and staggered) made of large cylindrical lithium iron phosphate cells (of 18 Ah nominal capacity) are analysed in this paper during a 90 A constant discharge current. The analysis of the battery packs temperature distributions is ... En savoir plus

The material wood is frequently used in construction industry for several elements such as window frames. However, as a hygrothermal material, wood is sensitive to moisture induced damage. In this context, the moisture uptake of wood based windows logged with an integrated relative ... En savoir plus