Are solid-state batteries really 3-5 years away? It seems like they've been 5 years away for the last 10 years.
If not, I'll probably have to wait it out haha. I think all the fuel and maintenance work savings are not going to eclipse the depreciation (owing to the battery pack) and battery pack replacement, if even available, down the road.
A deep research on battery pack failures on perplexity tells me BEVs are not really prime-time yet.
Comprehensive Enumeration of Battery Pack Failure Causes in Electric Vehicles
Electric vehicle battery packs are sophisticated energy storage systems comprising numerous cells, electronic components, and thermal management systems. Despite advancements in battery technology, these complex systems can fail due to various factors. This report identifies and categorizes the primary causes of battery pack failures in electric vehicles, drawing from current research and industry knowledge.
Thermal-Related Failure Mechanisms
Thermal issues represent one of the most significant categories of battery failure mechanisms in electric vehicles. Temperature extremes and management failures can rapidly compromise battery integrity.
Thermal Runaway Events
Thermal runaway occurs when heat generation within the battery exceeds its heat dissipation capacity, creating a potentially dangerous self-reinforcing cycle. This phenomenon is often considered the most critical failure mode and can lead to catastrophic consequences.
Loss of temperature control is cited as the main cause of battery failure, particularly in thermal runaway scenarios
[1]. When the internal temperature rises, chemical reactions accelerate, generating additional heat in a cascading effect. This process can eventually lead to fires, explosions, or the release of toxic gases
[2].
Extreme Temperature Exposure
Both high and low temperature extremes negatively impact battery performance and can accelerate degradation:
High temperatures accelerate side reactions within the cells, increasing the rate of lithium plating and intercalation into the anode
[3].
Low temperatures significantly impact battery chemistry, leading to the formation of "dead lithium" which contributes to capacity decay and solid electrolyte interphase (SEI) growth
[3].
Battery charging and discharging efficiency is substantially affected by extreme temperatures, whether during a "Norwegian winter" or a "Texas heat wave"
[4]. Manufacturers have responded by developing sophisticated thermal management systems to maintain optimal operating temperatures.
Physical Damage and Mechanical Failures
Physical integrity of the battery pack is crucial for safety and performance, with several failure modes stemming from mechanical damage.
Impact and Collision Damage
External impacts from collisions can compromise the structural integrity of battery packs. Failure in lithium-ion batteries is frequently associated with "a collision or impact that damages the pack"
[5]. Such damage can create internal short circuits or compromise cooling systems, potentially leading to thermal events.
Internal Structural Failures
Even without external damage, internal structural issues can develop:
Electrode material fracturing and pulverization, particularly on the anode current collector, has been identified as a primary contributor to battery failure through scanning electron microscope analysis
[3].
Rupture of cathode materials represents another significant mechanical failure mode within cells
[3].
Separator failure can occur when the thin material between positive and negative electrodes is compromised, allowing direct contact between components.
Charging and Discharging Irregularities
Improper charging and discharging patterns significantly impact battery longevity and can lead to premature failure.
Overcharging Issues
Overcharging represents a serious threat to battery health and safety:
Extreme overcharging can lead to severe overheating, with affected batteries becoming "seriously hot" with charging currents that "can reach 2A or more"
[1].
Micro-overcharging, a more subtle but equally damaging phenomenon, occurs when the battery management system cannot identify and address slightly overcharged cells
[3]. This condition "expedites the battery's aging process and accelerates the formation of the solid electrolyte interphase"
[3].
Discharge-Related Problems
Discharge patterns also impact battery health:
Over-discharge events strain battery chemistry and can lead to irreversible capacity loss
[5].
Research indicates that both full charging and full discharging are "damaging to battery life"
[4], suggesting that maintaining partial states of charge is preferable for longevity.
Electrochemical Degradation Mechanisms
Various electrochemical processes contribute to battery degradation and eventual failure over time.
Dendrite Formation
The growth of lithium dendrites—needle-like structures that form during charging—represents a significant failure mechanism:
During micro-overcharging cycles, "lithium plating takes place at the interface of the anode and the separator," leading to metallic lithium accumulation
[3].
Once this accumulation reaches a critical threshold, lithium dendrites emerge, creating a "significant risk of internal short circuits, battery malfunction, and thermal runaway events"
[3].
Studies using scanning electron microscopy have confirmed that "the number of lithium dendrites in the negative electrode increases during the ongoing process of micro-overcharge cycling"
[3].
Solid Electrolyte Interphase (SEI) Issues
The SEI layer—formed between the electrode and electrolyte—plays a crucial role in battery function:
Rapid formation and thickening of the SEI layer is associated with battery failure under micro-overcharging conditions
[3].
This thickening contributes to increased internal resistance and reduced capacity over time.
Battery Management System Failures
The sophisticated electronics that monitor and control battery operation can themselves become points of failure.
Control System Malfunctions
Battery management systems (BMS) serve as critical safeguards:
When the BMS fails to properly monitor and control cell balance, individual cells may experience minor degrees of overcharge or over-discharge
[5].
In scenarios where "the battery management system is unable to promptly identify and address overcharged cells," cycles of micro-overcharging can perpetuate, accelerating degradation
[3].
Thermal Management System Failures
Cooling systems are essential for maintaining optimal battery temperature:
Failure of thermal management components can prevent adequate heat dissipation, potentially leading to thermal runaway events.
After water loss in certain battery designs, "the heat generated inside the battery can only dissipate heat through the battery tank"
[1]. If heat dissipation becomes insufficient, temperature escalation follows.
Manufacturing and Design Factors
Inherent characteristics of battery design and production can contribute to failure susceptibility.
Cell Inconsistency Issues
Manufacturing variations between cells create vulnerabilities:
"Inherent inconsistencies among individual cells" within battery packs can lead to uneven charging and discharging patterns
[3].
These inconsistencies make it difficult for battery management systems to maintain optimal conditions across all cells.
Structural Design Compromises
Design choices may prioritize energy density at the expense of robustness:
To increase battery capacity, manufacturers may use "relatively thinner" partitions compared to other battery types, making them more vulnerable to damage
[2].
When these thin partitions are compromised, problems like "lead sulfate crystallization and growth" can occur, potentially leading to short circuits through a phenomenon called "lead branch bridging"
[2].
Maintenance and Usage Factors
How batteries are maintained and used significantly impacts their longevity.
Inadequate Maintenance
Proper battery maintenance is essential for longevity:
"Batteries that are overstocked and not maintained regularly" are prone to failure
[2].
Poor battery maintenance can directly contribute to internal short circuits that trigger thermal runaway events
[1].
Dehydration
Water loss within certain battery designs represents a specific failure mechanism:
After dehydration, "the ultrafine glass fiber partition in the battery shrinks, making the adhesion with the positive and negative plate worse"
[1].
This process increases internal resistance and heat generation during operation.
Since water has the "largest heat capacity in the battery," its loss significantly reduces the battery's ability to absorb and regulate heat
[1].
Conclusion
Battery pack failures in electric vehicles stem from a complex interplay of thermal, mechanical, electrochemical, and management factors. Understanding these diverse failure mechanisms is crucial for designing more robust systems and implementing effective preventive measures.
Modern electric vehicle manufacturers have responded to these challenges with sophisticated battery management systems, thermal regulation technologies, and structural protections. These advancements, coupled with standard industry warranties of "at least an eight-year, 100,000-mile warranty on EV battery packs"
[4], reflect growing confidence in addressing the major failure modes that once posed significant concerns for electric vehicle adoption.
As battery technology continues to evolve, ongoing research into failure mechanisms remains essential for developing increasingly reliable and safe energy storage solutions for electric vehicles.
⁂
https://semcouniversity.com/causes-of-battery-failure-in-electric-vehicles/
https://www.linkedin.com/pulse/common-failure-modes-amp-causes-electric-vehicle-batteries-
https://pmc.ncbi.nlm.nih.gov/articles/PMC11084451/
https://www.caranddriver.com/features/a31875141/electric-car-battery-life/
https://www.recurrentauto.com/research/deep-dive-battery-failure-mechanisms
