(1. 燕山大學(xué)國家冷軋板帶裝備及工藝工程技術(shù)研究中心，秦皇島 066004；
2. 邢臺納科諾爾精軋科技股份有限公司，邢臺 054000)
摘 要: 為闡明鋰離子電池極片輥壓過程微觀結(jié)構(gòu)演化與宏觀變形力學(xué)量化行為，通過分析變形區(qū)內(nèi)極片涂層和集流體形貌特征。結(jié)果表明：輥壓方向上活性顆粒密實度顯著增加，將輥壓對極片涂層的影響總結(jié)為碳膠相壓縮、活性顆粒破碎及融合為二次顆粒。集流體整體未發(fā)生減薄，由于石墨硬度小，負(fù)極銅箔表面高度起伏均在600 nm以內(nèi)，正極部分活性顆粒嵌入表面，最小涂層厚度時，正極部分活性顆粒嵌入表面的深度為2 μm。同時，將活性涂層壓縮簡化為平面變形問題，利用微分單元法和壓縮變形本構(gòu)模型，將變形區(qū)分成若干個微元并進(jìn)行受力分析，依此推導(dǎo)變形區(qū)壓力分布及軋制力計算公式，構(gòu)建單位軋制力與涂層厚度、壓實密度的關(guān)系模型，該模型可為實施AGC厚度精確控制及工藝優(yōu)化提供理論基礎(chǔ)。
關(guān)鍵字: 鋰電池極片；輥壓；單位軋制力；微觀結(jié)構(gòu)；壓下率
（1. National Engineering Research Center for Equipment and
Technology of Cold Strip Rolling, Yanshan University, Qinhuangdao 066004,
China;
2. Xingtai Naknor Technology Co., Ltd., Xingtai
054000, China）
Abstract:For clarifying the microstructure evolution and macroscopic deformation mechanical quantitative behavior of lithium-ion battery electrode during calendering process, the morphological characteristics of electrode coating and current collector in the deformation zone were analyzed. The results show that the denseness of active particles significantly increase in the calendering direction, and the effect of calendering on electrode coating is summarized as carbon-PVDF compression, active particle fragmentation and fusion into secondary particles. The overall current collector has not been thinned. Due to the small hardness of graphite, the surface height of the copper foil fluctuates within 600 nm, and some of the active particles of the cathode electrode are embedded in the surface, with an embedding depth of 2 μm at the minimum thickness. Meanwhile, the coating compression is reduced to a plane deformation, and the deformation zone is distinguished into several microelements and force analysis by using the differential unit method and the compression deformation intrinsic model. Based on this, the calculation formulas of pressure distribution and rolling force were derived, and the relationship model between unit rolling force and coating thickness and compaction density is constructed, which can provide the theoretical basis for the implementation of accurate control of AGC thickness and process optimization.
Key words: lithium-ion battery electrode; calendaring; unit rolling force; microstructure; reduction rate
