Methods and systems for redox flow battery electrolyte hydration

Abstract

Methods and systems are provided for transporting and hydrating a redox flow battery system with a portable field hydration system. In one example, the redox flow battery system may be hydrated with the portable field hydration system in a dry state, in the absence of liquids. In this way, a redox flow battery system may be assembled and transported from a battery manufacturing facility to an end-use location off-site while the redox flow battery system is in the dry state, thereby reducing shipping costs, design complexities, as well as logistical and environmental concerns.

1 . A method of operating a redox flow battery system, the redox flow battery system including first and second electrolyte chambers fluidly coupled to a redox flow battery cell, the method comprising:
 during a first condition as determined by a controller, including when the redox flow battery system is in a dry state without water and liquid solvents,   adding first and second amounts of dry electrolyte precursor to the first and second electrolyte chambers, respectively, the first and second amounts corresponding to a desired concentration of first and second electrolytes in the first and second electrolyte chambers during an operating mode, including when the redox flow battery system is being charged or discharged,   fluidly coupling the redox flow battery system to a field hydration system, the field hydration system detachably fluidly coupled to the first and second electrolyte chambers of the redox flow battery system and including a water supply pump detachably fluidly coupled to a water source,   supplying water from the field hydration system to the redox flow battery system, wherein the redox flow battery system would remain in the dry state without the water from the field hydration system,   while supplying water from the field hydration system, continuously monitoring a conductivity of the water via one or more conductivity sensors, and signaling if the conductivity of the water is greater than a threshold conductivity,   operating the redox flow battery system, wherein operating the redox flow battery system includes both charging by applying a charging current and discharging via oxidation and reduction of the first and second electrolytes.   
     
     
         2 . The method of  claim 1 , wherein supplying water from the field hydration system includes flowing water through a filtration system bifurcated into a first filter passage and a second filter passage positioned between the water source and the first and second electrolyte chambers. 
     
     
         3 . The method of  claim 2 , wherein water flowing through the first filter passage and the second filter passage is combined before flowing to the one or more conductivity sensors. 
     
     
         4 . The method of  claim 2 , wherein the one or more conductivity sensors includes a first conductivity sensor positioned immediately downstream of the first filter passage and a second conductivity sensor positioned downstream of the second filter passage. 
     
     
         5 . The method of  claim 2 , wherein signaling indicates degradation of the filtration system. 
     
     
         6 . The method of  claim 1 , wherein signaling includes sending an audio and/or visual signal to an operator. 
     
     
         7 . The method of  claim 1 , wherein adding the first and second amounts of dry electrolyte precursor is done at a manufacturing location or an end-use location. 
     
     
         8 . The method of  claim 1 , wherein supplying water from the field hydration system to the redox flow battery system includes stage-wise filling of the first and second electrolyte chambers. 
     
     
         9 . A redox flow battery system, comprising:
 a field hydration system that is separate from the redox flow battery system and detachably fluidly coupleable to positive and negative electrolyte chambers of the redox flow battery system, a redox flow battery cell fluidly coupled to the positive and negative electrolyte chambers;   dry electrolytes located in the positive and negative electrolyte chambers with less than a threshold amount of solvents;   the field hydration system detachably fluidly coupleable to a water source arranged externally to the redox flow battery cell;   the field hydration system including a filtration system bifurcated into a first filter passage and a second filter passage positioned between the water source and the positive and negative electrolyte chambers; and   a controller, including executable instructions stored thereon to,   activate a water supply pump of the field hydration system configured to flow water from the water source to the positive and negative electrolyte chambers;   charge by applied current and discharge the redox flow battery cell during operation.   
     
     
         10 . The redox flow battery system of  claim 9 , wherein a first three filters are positioned within the first filter passage and a second three filters are positioned with the second filter passage. 
     
     
         11 . The redox flow battery system of  claim 10 , wherein the first three filters and the second three filters are carbon filters or deionizing filters. 
     
     
         12 . The redox flow battery system of  claim 9 , wherein a conductivity sensor is arranged directly downstream of the filtration system. 
     
     
         13 . The redox flow battery system of  claim 9 , wherein the positive and negative electrolyte chambers each include a heater coupled to the controller. 
     
     
         14 . The redox flow battery system of  claim 9 , wherein the positive and negative electrolyte chambers are fluidly coupled to each other and a single heater is configured to heat liquid within both the positive and negative electrolyte chambers. 
     
     
         15 . A redox flow battery system, including first and second electrolyte chambers fluidly coupled to a redox flow battery cell, and a controller with executable instructions stored in non-transitory memory thereon to:
 during a first condition as determined by the controller, including when the redox flow battery system is in a dry state without water and liquid solvents,   add first and second amounts of dry electrolyte precursor to the first and second electrolyte chambers, respectively, the first and second amounts corresponding to a desired concentration of first and second electrolytes in the first and second electrolyte chambers during an operating mode, including when the redox flow battery system is being charged by applied current or discharged, fluidly couple the redox flow battery system to a field hydration system using one or more actuators controlled by the controller, the field hydration system detachably fluidly coupled to the first and second electrolyte chambers of the redox flow battery system and including a water supply pump detachably fluidly coupled to a water source,   flow water from the water source through a filtration system including a first filter passage and a second filter passage positioned between the water source and the first and second electrolyte chambers,   supply water from the field hydration system to the redox flow battery system, wherein the redox flow battery system would remain in the dry state without the water from the field hydration system,   operate the redox flow battery system in at least one operating mode in response to decoupling the field hydration system from the redox flow battery system.   
     
     
         16 . The redox flow battery system of  claim 15 , wherein the dry electrolyte precursor includes one or more of FeC12, FeC13, FeSO4, Fe2(SO4)3. 
     
     
         17 . The redox flow battery system of  claim 15 , wherein the field hydration system further includes one or more conductivity sensors positioned downstream of the first filter passage and the second filter passage. 
     
     
         18 . The redox flow battery system of  claim 15 , wherein the field hydration system further includes one or more level sensors communicatively coupled to the controller. 
     
     
         19 . The redox flow battery system of  claim 18 , wherein the controller further includes executable instructions to start and stop flow of water to the first and second electrolyte chambers in response to a signal from the one or more level sensors. 
     
     
         20 . The redox flow battery system of  claim 15 , wherein the controller further includes executable instructions to drain the first and second electrolyte chambers in response a desire to move a location of the redox flow battery system.