To improve the safety of electric vehicles and portable electronics, it is crucial to understand the mechanical behavior of the jelly-stack and develop predictive constitutive models at the cell level. Here, we investigate the effect of strain-rate and temperature on the force-displacement response and the challenge of predicting meaningful deformation kinematics using a homogenized model. An experimental investigation is carried out on 4 Ah Li-ion pouch cells using hemispherical indentation for temperature ranging from –5 °C to 70 °C, strain rates from 0.001 s⁻¹ to 1000 s⁻¹, and states of charge (SoC) from 0.0 to 0.97. The experiments highlight the dominant effects of temperature and strain rate, and the minor influence of the SoC. To capture these dependencies, a phenomenological constitutive model is proposed based on a pressure-sensitive yield surface with associated plastic flow. The convex-to-linear hardening transition is modulated by temperature and SoC, while Johnson–Cook-type multiplicative factors are used to describe the strain rate and softening effects. The proposed model shows good agreement with the observed force-displacement responses across all experiments. However, due to the layered nature of the jelly-stack, the cell kinematics cannot be accurately captured. Upon bending, individual layers slide along one another, leading to size effects that cannot be captured with a standard homogenized theory. We then develop a gradient-enhanced theory able of (i) differentiating between in-plane and out-of-plane shear loading, (ii) accounting for the individual layer bending and (iii) tracking interlayer sliding and delamination. The model is validated on hemispherical indentation experiments performed on aluminum sheet stacks, acting as mechanical analogue to lithium-ion cells. The characteristic upward motion is observed and compared to layer-resolved finite element simulations. The gradient-enhanced model provides equally meaningful predictions as the layer-resolved model for both in-plane and out-of-plane indentation, setting it apart from local models that can only be calibrated for specific loading conditions.