No abstract

Remarkable inhibition of the hydrogen evolution reaction (HER) is demonstrated on phosphorus-doped activated carbon, which shows great potential as an additive to the negative electrodes of lead-carbon batteries and other electrochemical applications.

Bi 2 O 2 CO 3 /Activated carbon (AC) composite is successfully synthesized via a facile hydrothermal method and investigated as an additive for lead-acid batteries for the first time. Remarkable inhibition of hydrogen evolution reaction (HER) is demonstrated on the optimized content of 4 wt% Bi 2 O 2 CO 3 /AC additive, which suppresses the hydrogen evolution current by 93.1% and increases the overpotential of HER by 230 mV. In addition, 2 V 7 Ah lead-acid module cell with 4 wt% Bi 2 O 2 CO 3 /AC additive maintains a lifespan up to 19637 cycles, confirming the feasibility to construct high performance lead-acid battery. The short cycle life of Valve-regulated lead-acid (VRLA) battery, especially at the high discharge rate or under high-rate partial-stateof-charge (HRPSoC) duty, is the main challenge for its hybrid electric vehicles (HEVs) and energy storage applications.1-3 Integrating appropriate content of carbon (activated carbon, carbon black, carbon nanotube and expanded graphite) into the negative-active-mass (NAM) of VRLA battery, has been demonstrated to be an effective way to alleviate the irreversible accumulation of lead sulfate on the negative plates, which is the major failure mode of VRLA battery, and thus improve HRPSoC performance. [4][5][6] However, high content carbon additive can cause side reactions of hydrogen evolution reaction at the end of charge process on the negative plates due to its low overpotential of hydrogen evolution, accelerating water loss and leading to battery failure, 7 which poses an urgent issue to be overcome. Hydrogen evolution inhibitor is preferentially adopted to relieve HER rate and prolong the battery cycle life. For example, Zhao et al. 8,9 demonstrated that adding Bi 2 O 3 , Ga 2 O 3 and In 2 O 3 can effectively suppress the HER rate at the negative plates with activated carbon additives and enhance the battery cyclability. Such HER inhibitors are usually introduced into negative plates by physical mixing or chemical depositing, 6 resulting in uneven distribution, which, to a certain extent, effects inhibition of HER and battery performance.In this work, we synthesize Bi 2 O 2 CO 3 modified activated carbon composite through a simple hydrothermal method, using Bi 2 (SO 4 ) 3 and AC as precursors. Belong to the Bi-based materials as Bi 2 O 3 , Bi 2 O 2 CO 3 consists of alternative stacking of (Bi 2 O 2 ) 2+ layers and slabs of CO 3 2− group. 10 With high capacitance performance and low hydrogen evolution ability, Bi 2 O 2 CO 3 /AC composite, is supposed to be a promising additive for the lead-acid batteries. To the best of our knowledge, Bi 2 O 2 CO 3 /AC as an additive to negative active mass for lead-acid battery has never been reported. ExperimentalMaterials synthesis.-The Bi 2 O 2 CO 3 /AC composites were synthesized using Bi 2 (SO 4 ) 3 and activated carbon (YP80F, Kuraray Co. Ltd.) as raw materials by a facile hydrothermal method. In a typical procedure, Bi 2 (SO 4 ) 3 was firstly dissolved into 70 mL distilled water to form a transparent solution at room tem...