Two main contexts: physics (
带正电 'positively charged',
带负电 'negatively charged') and electrical safety (
带电的电线 'live wire',
带电作业 'live-line maintenance work performed without cutting power'). The literal pattern
带 + X is productive —
带毒 'carries a virus / poison',
带菌 'carries bacteria',
带刺 'has thorns / is prickly'.