Formation is a critical step in battery manufacturing. During this process, lithium inventory is consumed to form the solid electrolyte interphase (SEI), which in turn determines the battery lifetime. To tackle the vast parameter space and complexity of formation, we employ a data-driven workflow on 186 lithium-ion battery cells across 62 formation protocols. We identify two key parameters, formation charge current and temperature, that control battery longevity via distinct mechanisms. Surprisingly, high-formation charge current on the first cycle extends battery cycle life by an average of 50%. Unlike elevated formation temperature, which boosts battery performance by forming a robust SEI, the cycle life improvement for fast-formed cells arises from a shifted electrode-specific utilization after formation. Apart from the widely acknowledged role of formation in governing SEI properties, we demonstrate how formation protocols determine the stoichiometry range over which the positive and negative electrodes are cycled.

中文翻译：

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电池形成的数据驱动分析揭示了电极利用率在延长循环寿命方面的作用


化成是电池制造的关键步骤。在此过程中，锂库存被消耗以形成固体电解质界面 （SEI），这反过来又决定了电池寿命。为了解决巨大的参数空间和化成的复杂性，我们对 62 个化成协议中的 186 个锂离子电池单元采用了数据驱动的工作流程。我们确定了两个关键参数，化成电荷电流和温度，它们通过不同的机制控制电池寿命。令人惊讶的是，第一个周期的高形成充电电流将电池周期寿命平均延长了 50%。与通过形成稳健的 SEI 来提高电池性能的升高化成温度不同，快速形成电池的循环寿命改善是由于形成后电极特异性利用率的转移而产生的。除了广泛认可的形成在控制 SEI 特性中的作用外，我们还展示了形成方案如何确定正极和负极循环的化学计量范围。