Mining Contract: Multi-cell lithium ion battery safety enhancement for underground mining applications via dell-to-cell isolation during thermal runaway

Contract Status & Impact

This contract is complete. To receive a copy of the final report, send a request to mining@cdc.gov.

Fires and explosions of lithium-ion batteries continue to present a risk for underground mining operations. A better understanding of damage parameters precipitating failure, as well as methods of isolating and encapsulating batteries in order to keep them from cascading nearby batteries into thermal runaway is needed. 

Over the course of a two-year contract, ADA Technologies pursued specific technical milestones and accomplished specified tasks.

Technical Milestones:

• Utilize and further develop ADA's CIM (Cell Isolation Material) into a unique multi-‘bilayer’ isolation material system (the M-BIM format) to provide cascading thermal runaway prevention for large format lithium ion batteries in relevant formats for cells used in mining equipment. Demonstrate the advantages/disadvantages of CIM coated on Cu substrate versus highly conductive graphitic thermal pads, so that a thermally conductive substrate prevents ADA CIM encapsulated cells from heating up during normal operation conditions.
• Demonstrate using ADA's already established and installed automated laser electrode cutter (ALEC), the feasibility of fabricating custom-cut seams in case of thermal runaway cell isolation materials to facilitate agile manufacturing of CIMs for protection of Li-ion cells with a variety of architectures, specific to mining applications.

Tasks:

• Task 1: Establishment of failure modes in typical mining power sources through battery abuse tests. In this task, ADA will acquire commercial off the shelf (COTS) LFP cells which are widely utilized for assembling commercial Li-ion systems, to demonstrate failure characteristics, thermal runaway and dangers of overcharging/overheating when unprotected.
• Task 2: ADA's multi-layer CIM (MBIM) performance in preventing cell-to-cell communication. In this task, ADA proposes to enhance our CIM technologies to fit prismatic and cylindrical format batteries and include an M-BIM approach rather than a bilayer CIM approach, specifically for enhanced protection in mining environments. The proposed effort will include material formulation and coating methods development. Specifically, ADA proposes to create a coating system that allows for consistent coating with tight thickness tolerances and high repeatability.
• Task 3: Implementation of CIM into relevant battery pack in partnership with relevant battery manufacturer. In this task, ADA will pick one battery manufacturer with a relevant battery system used or to be used in a mining application for demonstration of CIM performance. ADA will test materials for adhesion, durability, and uniformity after coating. Rigorous testing will be performed to validate ADA's M-BIMs. ADA has significant experience with battery failure and cell isolation material testing, and is capable of performing overheat, overcharge, crush, and penetration cell failure testing in-house.
• Task 4: Establishment of material properties to meet or exceed mining environmental conditions. In this task, several test conditions (abuse, overstressing cells, simulation of manufacturing defect related failure, etc.) will be used to ensure safety requirements are met.
• Task 5: Demonstration of safe battery operation unhindered by ADA's CIMs. In this task, ADA will "stress test" LFP cells typically used by mining equipment/drilling industries for safe performance demonstration with and without ADA CIMs to ensure that CIM integration does not unnecessarily stress Li ion cells when they are undergoing light to heavy duty charging and discharging cycles within safety recommendations.
• Task 6: Expanded fire and thermal isolation performance tests for technology maturation. In this task, ADA will establish battery pack normal operation performance as well as thermal mitigation of ADA CIMs during failure in a relevant battery configuration for mining applications.