Chemical reactions in solids can induce chemical expansion of the solid that causes the emergence of the mechanical stresses, which, in turn, can affect the rate of the reaction. A typical example of this is the reaction of Si lithiation, where the stresses can inhibit the reaction up to the reaction locking. The reactions in solids can take place within some volume (bulk reactions) or localise at a chemical reaction front (localised reactions). These cases are typically described by different thermo-chemo-mechanical theories that contain the source/sink terms either in the bulk or at the propagating infinitely-thin interface, respectively. However, there are reactions that can reveal both regimes; hence, there is a need to link the theories describing the bulk and the localised (sharp-interface) reactions. The present paper bridges this gap and shows that when a certain structure of the Helmholtz free energy density is adopted (based on the ideas from the phase-field methods), it is possible to obtain (in the limit) the same driving force for the chemical reaction (hence, the same reaction kinetics) as derived within the theory of the sharp-interface chemical reactions based on the chemical affinity tensor.

固体中的化学反应会引起固体的化学膨胀，从而导致机械应力的出现，进而影响反应速率。一个典型的例子是硅锂化反应，其中应力可以抑制反应直至反应锁定。固体中的反应可以在一定体积内发生（本体反应）或集中在化学反应前沿（局部反应）。这些情况通常由不同的热化学机械理论来描述，这些理论分别包含本体或传播无限薄界面处的源/汇项。然而，有些反应可以揭示这两种制度；因此，需要将描述本体反应和局部（尖锐界面）反应的理论联系起来。本文弥补了这一差距，并表明当采用某种亥姆霍兹自由能密度结构时（基于相场方法的思想），可以获得（在极限内）相同的驱动力化学反应（因此，相同的反应动力学）与基于化学亲和力张量的锐界面化学反应理论中导出的化学反应相同。