Local Entropy Offloading in Open Solid-State Electrochemical Systems: The Structural Invariance of Fundamental Charge Carriers

Existing literature on electrochemical cell degradation primarily relies on macro-scale chemical thermodynamics and empiricalphenomenological models. However, these models fail to articulate the microscopic entropy partition mechanisms occurring at thesingle-carrier boundary. Here, we present a fundamental quantum-thermodynamic framework establishing that fundamental chargecarriers (electrons) possess absolute zero intrinsic entropy change (ΔSintrinsic = 0) during transport due to their lack of internalmicrostates. Since fundamental particles maintain structural invariance, the total entropy generated via electrochemical potentialgradients cannot be absorbed by the electron cloud and is instead completely offloaded to the open solid-state system—specificallyinto lattice phonon emission, Solid Electrolyte Interphase (SEI) growth, and irreversible structural defects. We formulate a quantitativemathematical model coupling the quantum invariance of charge carriers with the local heat-dissipation and degradation equations insolid-state electrodes. Finally, we map this theoretical framework to advanced Battery Management System (BMS) algorithms,providing a unified physical bridge between Coulomb counting and potential-driven degradation.