Capacity fade refers to the reduction in the amount of charge a battery can hold as it ages and is cycled. Over time and repeated charge/discharge cycles, various degradation mechanisms (like loss of active lithium, structural changes in electrodes, SEI growth on anodes, or electrolyte decomposition) permanently consume some of the battery’s capacity. As a result, a fully charged, aged battery delivers less energy than when it was new, under the same test conditions. Capacity fade is usually measured by comparing the battery’s current capacity in Ah or Wh, to its original capacity, often expressed as a percentage. End-of-life commonly defined when the cell capacity, measured in Ah, falls to around 80% of its original value.
NOVONIX measures capacity fade through long-term cycling tests and by using its Ultra-High Precision Coulometry (UHPC) equipment. By using UHPC equipment to detect extremely small losses per cycle, NOVONIX can project comparative long-term capacity retention without having to wait for months or years of cycling. In its research, NOVONIX examines how various materials (such as advanced cathodes or electrolyte additives) and usage conditions (including depth of discharge and temperature) affect capacity fade rates. These insights help battery materials developers improve their material properties to be able to achieve excellent long term cell performance.. NOVONIX assists clients in benchmarking their cells’ capacity fade against industry standards, guiding improvements needed to meet warranty and performance targets for products like EVs or grid storage batteries.
