Substrate materials and novel designs for bipolar lead-acid batteries: A review

Despite lead-acid production facilities being quite appealing in terms of scale, cost, and recycling; low energy density positions the lead-acid battery at the bottom of the Ragone plot of electrochemical systems. Several industrial and academic research efforts are continuing for the past few decades for tapping its storage capacity by developing bipolar lead-acid batteries. However, bipolar architecture demands a lightweight bipolar substrate with excellent corrosion resistance and structural stability, which thereby presents challenges, namely leak-proof sealing and active paste adherence. Unresolved challenges are the reasons for the confinement of the bipolar lead-acid batteries to laboratory curiosity or laboratory prototypes for the past few decades. However, recently few inventors are successfully leading the way to overcome the age-old hurdles of technical challenges, commercial production, and long battery life. This article highlights recent advances as well as past inventions of bipolar lead-acid battery with respect to substrate material, designs, and sealing techniques.