Boron doped graphene nanosheets as negative electrode additive for high-performance lead-acid batteries and ultracapacitors

• Published in: Journal of alloys and compounds 2019-08, Vol.797, p.595-605
• Main Authors: Naresh, Vangapally, Bhattacharjee, Udita, Martha, Surendra K.
• Format: Article
• Language: English
• Subjects: Acids; B-doped graphene nanosheets; Batteries; Boron; Charge materials; Discharge; Electrochemical analysis; Electrodes; Failure modes; Graphene; Hole conductivity; HRPSoC cycling; Hydrogen evolution; Lattice vibration; Lead acid batteries; Nanosheets; Negative electrode additive; Sulfation; Supercapacitor; Supercapacitors
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.04.311

Sulfation at the negative electrode is one of the major failure modes of lead-acid batteries. To overcome the issues of sulfation, in this work we synthesize Boron doped graphene nanosheets as an efficient negative electrode additive for lead-acid batteries. 0.25 wt % Boron doped graphene nanosheets additive in negative electrode which contains around 3% of Boron doping shows impressive electrochemical performance in first discharge capacity, ∼60% increase the capacity in relation to the conventional lead-acid cell. Noticeably, 15–20% enhancement in the discharge capacity at lower C rates and almost double increase in capacity at higher C rates show Boron doped graphene nanosheets as a potential additive for lead-acid battery operating under high rate partial state of charge applications. The superior electrochemical performance is due to the p-type or hole conductivity of the Boron doped graphene lattice, which reduces lead sulfate formation and thereby enhances active material utilization, charge acceptance, and reduces hydrogen evolution. Besides, the high C-rate performance of Boron doped graphene nanosheets additive cell is due to the capacitive property of Boron-doped graphene nanosheets which delivers specific capacitance of 90 F g−1 at 2 A g−1 with >75% capacity retention at the end of 2000 cycles. Schematic of the synthesis of BGNS from graphite powder. [Display omitted] •BGNS enhances the conductivity, charge storage property, access to the electrolyte.•BGNS in NAM improves the active material utilization and high C rate performances.•0.25 wt% of BGNS additive to NAM delivers 63% increment in HRPSoC cycling.•BGNS in NAM reduces hydrogen evolution, thereby increases charge acceptance.•BGNS shows a specific capacitance of 90 F g−1 over 2000 cycles at 2 A g−1.