Using silkworm excrement and spent lead paste to prepare additives for improving the cycle life of lead-acid batteries

Abstract

Abstract Sulfation at the negative electrode remains a crucial failure in lead-acid batteries. To overcome the sulfation issue, herein, a silkworm excrement-based porous carbon (SEPC) material has been successfully synthesized by a facile one-step metal catalytic cracking method. Consequently, SEPC and desulfurization spent lead paste were mixed and calcined to obtain a composite material of SEPC and PbO (SEPC-PbO), and employed as the negative additive to suppress the sulfation of lead-acid battery. The morphological characterization exhibits that SEPC has a plentifully mesoporous structure. The specific discharge capacity of the SEPC-PbO negative plate is 165 mAh g−1 (11.5% higher than the negative plate of traditional lead-acid battery) and ensuring remarkable suppression of hydrogen evolution. After 400 100% depth of discharge (DOD) cycles, the capacity retention rate is still as high as 84% and after 3000 5%DOD cycles, the active substances of the SEPC cell remained high reversible. In addition, the development of new lead-acid batteries, the synthesis of biochar materials, and the combination of waste lead paste recycling industries were explored. All these contribute to the decrease of the pollution risk of the silkworm breeding and lead-acid battery recovery industry and revolutionize the sustainable utilization of carbon resources.