Batteries are valued as devices that store chemical energy and convert it into electrical energy. Unfortunately, the standard description of electrochemistry does not explain specifically where or how the energy is stored in a battery; explanations just in terms of electron transfer are easily shown to be at odds with experimental observations. Importantly, the Gibbs energy reduction in an electrochemical reaction in a battery also involves atom transfer between different phases. It is shown that, for simple galvanic cells or batteries with reactive metal electrodes, two intuitively meaningful contributions to the electrical energy are relevant: (i) the difference in the lattice cohesive energies of the bulk metals, reflecting metallic and covalent bonding and accounting for the atom transfer, and (ii) the difference in the ionization energies of the metals in water, associated with electron transfer. The ionization energy in water can be calculated as the sum of gas-phase ionization energies and the hydration energy of the metal ion. Entropy plays only a limited role, for instance, driving the processes in concentration cells. The prediction of the energy of batteries in terms of cohesive and aqueous ionization energies is in excellent agreement with experiment. Since the electrical energy released is equal to the reduction in Gibbs energy, which is the hallmark of a spontaneous process, the analysis also explains why specific electrochemical processes occur. In several important cases, including the classical Zn/Cu battery, the difference in the bulk-metal cohesive energies is the origin of the electrical energy released. For instance, metallic Zn, Cd, or Mg lack stabilization by bonding via unoccupied d-orbitals and are therefore of higher energy than most transition metals. Indeed, metallic zinc is shown to be the high-energy material in the alkaline household battery. The lead–acid car battery is recognized as an ingenious device that splits water into 2 H⁺(aq) and O^2– during charging and derives much of its electrical energy from the formation of the strong O–H bonds of H₂O during discharge. The analysis provides an explanation of basic electrochemistry that will help students better understand this important topic.

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电池如何存储和释放能量：解释基本的电化学

电池被视为存储化学能并将其转换为电能的设备。不幸的是，电化学的标准描述没有具体说明能量在何处或如何存储在电池中。仅就电子转移而言的解释很容易证明与实验观察结果不一致。重要的是，电池电化学反应中吉布斯能量的减少还涉及不同相之间的原子转移。结果表明，对于具有反应性金属电极的简单原电池或电池，对电能的两个直观上有意义的贡献是相关的：（i）散装金属的晶格内聚能的差异，反映了金属和共价键的结合，并说明了原子转移 （ii）水中金属离子电离能的差异，与电子转移有关。水中的电离能可以计算为气相电离能与金属离子的水合能之和。熵仅起到有限的作用，例如，驱动浓缩池中的过程。根据内聚和水离子化能量对电池能量的预测与实验非常吻合。由于释放的电能等于自发过程的标志，即吉布斯能量的减少，因此分析还解释了为什么发生特定的电化学过程。在一些重要的情况下，包括经典的Zn / Cu电池，块状金属内聚能的差异是释放出的电能的来源。例如，金属Zn，Cd或Mg缺乏通过未占据的d轨道进行键合的稳定性，因此比大多数过渡金属具有更高的能量。实际上，已证明金属锌是碱性家用电池中的高能量材料。铅酸汽车电池被认为是将水分解为2 H的灵巧设备。⁺（aq）和O ^2–在充电过程中，并从放电过程中H ₂ O的强O–H键的形成中获取大量电能。分析提供了基本电化学的解释，这将有助于学生更好地理解这一重要主题。