Significant life extension of lithium-ion batteries using compact metallic lithium reservoir with passive control

Both traditional graphite-based lithium-ion batteries and next generation silicon-based chemistries suffer significant capacity fade from loss of cyclable lithium due to continued solid-electrolyte interphase growth. A possible engineering solution to maintaining the capacity of cells is incorporating a metallic lithium reservoir and discharging the reservoir into a working electrode to make up for lost cyclable lithium. Here, metallic lithium reservoirs are inserted into both pouchand cylindrical-format cells. Significant capacity recovery and lifetime extension are demonstrated for traditional graphite and Si/graphite-based cells. A combination of post-mortem characterization and modeling provide insight into how the lithium distribution as a function of position from reservoir vary with recovery rate. The potential of using passive control to potentially eliminate the need for extra wiring for the third electrode is explored using a simple resistor. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study investigates the use of metallic lithium reservoirs to supplement lost cyclable lithium in lithium-ion batteries, demonstrating significant capacity recovery and extension of lifetime for traditional graphite and Si/graphite-based cells. Post-mortem characterization and modeling provide insights into the lithium distribution variations with recovery rate from the reservoir. The potential of passive control to potentially eliminate the need for extra wiring for the third electrode is explored using a simple resistor.