Strain Analysis on Electrochemical Failures of Nanoscale Silicon Electrode Based on Three-Dimensional In Situ Measurement  
[PERSON]  
1 Department of Mechanics, School of Mechanical Engineering, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin 300350, China; [EMAIL_ADDRESS] (Z.Q. ); [EMAIL_ADDRESS] (W.M. ); [EMAIL_ADDRESS] (L.L. ); [EMAIL_ADDRESS] (S.W);
[PERSON]  
[PERSON]  
3 School of Chemical Engineering and Technology, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin 300350, China; [EMAIL_ADDRESS] (Z.Q. ); [EMAIL_ADDRESS] (W.M. ); [EMAIL_ADDRESS] (L.L. ); [EMAIL_ADDRESS] (S.W);  
[PERSON]  
1 Department of Mechanics, School of Mechanical Engineering, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin 300350, China; [EMAIL_ADDRESS] (Z.Q. ); [EMAIL_ADDRESS] (W.M. ); [EMAIL_ADDRESS] (L.L. ); [EMAIL_ADDRESS] (S.W);  
[PERSON]  
1 Department of Mechanics, School of Mechanical Engineering, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin 300350, China; [EMAIL_ADDRESS] (Z.W. );  
2 Tianjin Key Laboratory of Modern Engineering Mechanics, School of Mechanical Engineering, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin 300350, China  
3 School of Chemical Engineering and Technology, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin 300350, China; [EMAIL_ADDRESS] (Z.W. );  
2 Tianjin Key Laboratory of Modern Engineering Mechanics, School of Mechanical Engineering, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin 300350, China  
3 School of Chemical Engineering and Technology, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin 300350, China; [EMAIL_ADDRESS] (Z.W. );  
structures of the silicon and the lithium ions during charging/discharging process are of main concern, based on either the elasticity or diffusion theories. Specifically, [PERSON] et al. and [PERSON] proposed an analytical method that describes the dynamic process of the silicon particles and lithium ions [19; 20]. [PERSON] and [PERSON] established a mechanical-chemical coupling model based on the elastoplastic theory [21; 22; 23]. [PERSON] developed the electrochemical-mechanical coupling model, by which the influence of the elastic modulus on diffusion phenomena has been investigated [24]. [PERSON] and [PERSON] et al. investigated the stress distributions in LIBs by a traditional cantilever model, while the rigidity evolution of the silicon anode has been also obtained [25; 26]. [PERSON] et al. analyzed the insertion-induced stress in a Si anode and the interfacial decohesion effect of a silicon thin film electrode adhesively bonded to a rigid substrate using finite element analysis (FEA) [27]. [PERSON] investigated the influence of the anode density on the LIBs capacity and cycle life [16]. In the experimental aspect, the studies mainly focus on in situ observations and measurements of the anode deformation, phenomenologically or quantificationally. On the one hand, the fracture/cracking phenomena of the Si anode have been characterized phenomenologically through various imaging systems, including the atom force microscope (AFM) [8] and the optical microscope [28]. On the other hand, the anode deformation/deflection have been measured quantificationally to depict the mechanical behavior of the Si anode combining with the modelling calculations [8; 25; 28; 29; 30; 31]. Furthermore, some researchers were inspired by nanotechnology and consequently optimized the nanostructures of Si anode to improve the LIBs cycling performance [5; 6; 32]. A key factor to comprehensively understand the failure mechanism of the Si anode is that the full field deformation and the three-dimensional (3D) shape can be characterized quantificationally in real time during the lithiation/delithiation processes. Traditional full field displacement/strain measurement techniques are mostly based on optical methods, such as DIC (digital image correlation) [33; 34], Moire methods [35; 36; 37; 38] and grid methods [39; 40].