大学化学 >> 2026, Vol. 41 >> Issue (10): 423-429.doi: 10.12461/PKU.DXHX202511021

师生笔谈 上一篇    

如何判别化学电源的能斯特方程中固/液纯相物质的活度？

吕东生, 高爱梅   

  1. 华南师范大学化学学院, 广东 广州 510006
  • 收稿日期:2025-11-03 录用日期:2025-12-18 发布日期:2026-10-13
  • 通讯作者: 吕东生 E-mail:dhx@scnu.edu.cn Dongsheng Lu
  • 基金资助:
    华南师范大学质量工程建设项目(2023)；广东省科产教融合实践教学基地(202412)

How to determine the activity of solid/liquid pure phase substances in the Nernst equation for chemical power sources

Dongsheng Lu, Aimei Gao   

  1. School of Chemistry, South China Normal University, Guangzhou 510006, Guangdong Province, China
  • Received:2025-11-03 Accepted:2025-12-18 Published:2026-10-13
  • Contact: Dongsheng Lu E-mail:dhx@scnu.edu.cn

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摘要： 应用能斯特方程计算非标准态下化学电源的电动势时，常常需要判别方程中固/液纯相物质的活度然后进行简化。但是，现有的《物理化学》和《电化学原理》教材都没有涉及如何区分电池反应中反应物和生成物哪些是液体纯相，哪些是固体纯相，这使学生在简化能斯特方程时容易出现错误。针对这一问题，本文列举了铅酸蓄电池、锌镍蓄电池、锂离子蓄电池和钠硫蓄电池四种典型的化学电源的能斯特方程的简化方法，总结了方程中纯固相或液相活度的判别依据。

关键词: 能斯特方程, 可逆电极, 化学电源, 电池电动势, 活度

Abstract: When applying the Nernst equation to calculate the electromotive force of chemical power sources under non-standard conditions, it is essential to determine the activity of solid/liquid pure phase substances in the equation for proper simplification. Current textbooks on Physical Chemistry and Principles of Electrochemistry, however, fail to provide guidance on distinguishing between pure liquid and solid phases among reactants and products in battery reactions. This omission frequently leads to errors during students’ attempts to simplify the Nernst equation. To address this issue, this paper systematically examines four representative chemical power sources—lead-acid batteries, zinc-nickel batteries, lithium-ion batteries, and sodium-sulfur batteries—demonstrating their respective Nernst equation simplification methods. Furthermore, it establishes clear criteria for identifying the activity of pure solid or liquid phases within the equation.

Key words: Nernst equation, Reversible electrode, Chemical power source, Electromotive force of cell, Activity