Pressure Evolution in Constrained Rechargeable Lithium-metal Pouch Cells

Abhi Raj, Charles Dickerson, Shrikant Nagpure, Sangwook Kim, Jie Xiao, Boryann Liaw, Eric Dufek, Chaojiang Niu

January 2020 - Understanding the role of pressure on improving cycle life for high energy rechargeable lithium metal batteries (LMBs) is crucial for their adoption in practical applications. In this work, a fixed-gap test fixture is developed to monitor stack pressure of a multi-layer, 300 Wh kg−1 LMB over 245 cycles. During early cycling, a linear fade in discharge capacity is mirrored by a steady increase in baseline pressure. In later cycles, cell failure is linked to a large increase in baseline pressure due to irreversible side reactions such as continued SEI formation and gas evolution, as corroborated by incremental capacity analysis.

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