RECHARGEABLE CO2 BATTERY FOR INCREASED PRODUCTIVITY AND EFFICIENCY IN CONTROLLED ENVIRONMENT AGRICULTURE

Indoor farming systems require controlled dosing of CO2 to maintain concentrations beneficial to plant growth. A shipping container can require 3 kg of supplemental CO2 per day, while a small greenhouse can require as much as 200 kg of supplemental CO2 per day. Currently, this is accomplished either by transporting compressed CO2 gas to a growing facility, or through combustion of natural gas or propane. In most cases, a CO2 sensor controls a CO2 generator that burns natural gas or propane to produce CO2. A lithium carbon dioxide (Li-CO2) battery is an ideal solution to address the dual challenges of CO2 generation and reducing energy consumption. A Li-CO2 battery captures CO2 from the air to be later released into the growing space. In the process, the Li-CO2 battery provides energy during the CO2 capture process which could be used to support the CEA systems power needs. In Phase I Giner Labs will develop a novel Li-CO2 battery to capture and release CO2 to increase production in controlled agricultural environments, while providing energy that can be utilized to power the facility.Based upon the more mature Li-air battery technology, Li-CO2 and Li-CO2/O2 batteries utilize CO2 as an active cathode material, and during discharge, convert CO2 to Li2CO3. The conversion of CO2 to Li2CO3 generates energy, thereby acting as an energy storage device as well as a carbon capture device. In Phase I, Giner will develop a novel cathode for Li-CO2 battery and demonstrate reversible CO2 capture and controlled release in a small scale (coin cell) Li-CO2 battery.To accomplish this, Giner Labs has identified goals and measurable milestone metrics for each.Goal 1. Develop and characterize porous IL-GPE materials.Objective 1: Fabricate IL-GPE with bulk conductivity >10-2 mS/cm, 100% elongation before breaking, and which is electrochemically stable between 2.5-4.4 V. Down select three IL-GPE materials to incorporate into electrodes.Goal 2. Fabricate and characterize IL-GPE composite cathodes.Objective 2: Fabricate mechanically stable cathode electrode with >50% porosity and electrical conductivity >1 mS/cm.Goal 3. Electrochemically evaluate cathodes in full Li-CO2 cells.Objective 3: Demonstrate 50 discharge/charge cycles to 500 mAh/g with >95% CO2 recovery. Goal 4. Perform postmortem analysis of cycled components.Objective 4. Identify failure mechanisms for Li-CO2 IL-GPE cathode electrodes.Goal 5. Perform technoeconomic feasibility study.Objective 5. Complete feasibility study, identifying targets met and recommend mitigation or improvement strategies where the technology is found to fall short of targets.Once developed, the proposed Li-CO2 battery is expected to reduce costs in CEA facilities in three main categories:Dehumidification and cooling are reduced, leading to an expected reduction in electricity consumption from 3.92 Wh/m2 to 3.28 Wh/m2 a 16% reduction in electricity consumption.Realize an additional 2-5% reduction in due to renewable energy storage.CO2 supply costs would also be reduced by 45% by switching from natural gas consumption