Zhang Kai, He Yinan, Zhou Junwu, Wang Xinyang, Li Yong, Yang Fuqian
School of Aerospace Engineering and Applied Mechanics, Tongji University Shanghai 200092 China.
School of Intelligent Manufacturing and Control Engineering, Shanghai Polytechnic University Shanghai 201209 China
RSC Adv. 2024 Sep 20;14(41):29979-29991. doi: 10.1039/d4ra05354k. eCollection 2024 Sep 18.
Controlling the stress state of electrodes during electrochemical cycling can have a positive effect on the cycling performance of lithium-ion battery. In this work, we study the cycling performance of silicon-based lithium-ion half cells under the action of pressure in a range of 0.1 to 0.4 MPa. The cycling performance of the silicon-based lithium-ion half cells increases first with increasing the pressure to 0.2 MPa and then decreases with further increasing the pressure. The analysis of the surface morphologies of cycled electrodes reveals that applying a pressure of 0.2 MPa leads to the formation of fine electrode surface with the least surface cracks after the silicon-based lithium-ion half cells are cycled for 50 times, which supports the dependence of the cycling performance of the lithium-ion half cells on the pressure. The numerical results from the single particle model reveal that applying pressure can tune the stress state in a single electrode particle and reduce the tensile stress. However, the numerical results from the two-particle model point to that applying pressure can introduce tensile stress in the electrode particles due to contact deformation. Suitable pressure applied onto a lithium-ion battery is needed in order to improve the cycling performance of the lithium-ion battery without causing detrimental effects.
在电化学循环过程中控制电极的应力状态对锂离子电池的循环性能会产生积极影响。在这项工作中，我们研究了硅基锂离子半电池在0.1至0.4 MPa压力作用下的循环性能。硅基锂离子半电池的循环性能起初随着压力增加至0.2 MPa而提高，随后随着压力进一步增加而降低。对循环后电极表面形貌的分析表明，在硅基锂离子半电池循环50次后，施加0.2 MPa的压力会导致形成表面裂纹最少的精细电极表面，这支持了锂离子半电池循环性能对压力的依赖性。单粒子模型的数值结果表明，施加压力可以调节单个电极颗粒内的应力状态并降低拉应力。然而，双粒子模型的数值结果指出，由于接触变形，施加压力会在电极颗粒中引入拉应力。为了提高锂离子电池的循环性能而不产生有害影响，需要对锂离子电池施加合适的压力。
