Electrodegrade

Electrodegrade is a term used in electrochemistry to describe the degradation of an electrode during operation, including material loss, structural changes, and surface modifications that diminish performance. It can refer to the degradation process itself or to the degraded material and products that accumulate at the electrode–electrolyte interface.

Causes and mechanisms of electrodegrade vary by system but commonly include chemical corrosion, mechanical wear, dendrite formation, gas evolution, and dissolution of active material. In aqueous systems, anodic dissolution and corrosion can erode electrode surfaces, while in nonaqueous batteries, growth of insulating or resistive surface layers (such as a solid-electrolyte interphase) and crack formation can increase impedance and reduce capacity. Dendrite formation during charging can create shorts, and high potentials or aggressive electrolytes can accelerate material loss. The specific pathways depend on electrode composition, electrolyte, temperature, and operating voltage.

Contexts and examples of electrodegrade include energy storage devices, electroplating, and electrolysis. In lithium-ion batteries, electrodegrade manifests as SEI growth on graphite anodes, loss of active material from cathodes, lithium plating, and structural damage to particles, all contributing to capacity fade and higher resistance. In electroplating or corrosion-prone environments, electrode surfaces may experience metal dissolution or passivation layer breakdown, affecting efficiency and longevity.

Implications and mitigation strategies focus on extending device life and safety. Approaches include developing more stable electrode materials and coatings, optimizing electrolyte formulations and additives, controlling operating voltage and temperature, and designing architectures that accommodate or minimize mechanical stress. Ongoing research aims to better understand degradation pathways to tailor materials and operating conditions that reduce electrodegrade.