Rethinking Battery Technology for Electrification

The Growing Need for Advanced Battery Technology

A worldwide shift towards greater electrification is driving up the need for batteries that both last longer and charge more rapidly. This demand spans numerous sectors, including transportation, consumer electronics, medical equipment, and home energy storage solutions.

Although the advantages of this transition are widely recognized, battery technology has not yet advanced at the same rate as societal goals.

The Urgency of Climate Goals

Recent projections indicate a 40% probability of exceeding the 1.5 degrees Celsius temperature limit established by the Paris Agreement within the next five years. This underscores the critical need for accelerated development of next-generation battery technologies.

Fully commercializing these advanced batteries can require a decade or more, leaving limited time to address the climate challenge.

A Novel Approach to Battery Development

To effectively address the increasing pressure for electrification, a fundamentally new method of battery construction is essential.

Only through a completely innovative approach can the production of rechargeable batteries be scaled sufficiently to reduce global greenhouse gas emissions and mitigate the most severe consequences of the climate crisis.

Rapid innovation in battery technology is no longer simply desirable, but a necessity for a sustainable future.

Obstacles in Battery Technology Advancement

Significant financial investment, spanning several decades, has been directed by battery specialists, automotive manufacturers, component suppliers, and investors towards the development of advanced battery technologies. The primary focus has been on advancements in battery chemistry. Despite this, the industry continues to encounter two key technical hurdles that are hindering widespread battery adoption.

Fundamental Technical Challenges

These challenges significantly impact the potential of battery technology and its integration into various applications.

• Energy vs. Power Density: A fundamental limitation of current battery designs is the inherent trade-off between energy and power density. Batteries are engineered to either maximize energy storage capacity or prioritize rapid charging and discharging capabilities.

For electric vehicles, this presents a dilemma: achieving both extended driving range and swift recharge times remains elusive with existing battery technology.

• Anode and Cathode Imbalance: Contemporary battery technologies concentrate on enhancing the energy density of the anode, which serves as the negative electrode within a lithium-ion battery cell.

Currently, anodes already possess a higher energy density compared to the cathode, the positive electrode. To fully realize the potential energy storage capacity of a given battery size, the energy density of the cathode must ultimately align with that of the anode.

Implications for Future Battery Development

Without substantial progress in increasing cathode energy density, the full capabilities of many promising battery technologies will remain unrealized.

The prevalent lithium-ion battery, in its current form, is insufficient to meet the diverse requirements of a fully electrified future. Numerous organizations have attempted to overcome these limitations through innovative battery chemistries, aiming to optimize the power-to-energy density ratio with varying levels of success.

However, few have come close to achieving the performance benchmarks necessary for large-scale production and widespread commercial availability.

The Promise and Challenges of Solid-State Batteries

For some time, battery scientists have considered the solid-state battery to be a pivotal advancement in energy storage, offering the potential for both greater energy density and enhanced safety features. Despite this promise, practical implementation has proven challenging until recently.

A key advantage of solid-state batteries lies in their superior energy density and inherent safety, stemming from the elimination of flammable liquid electrolytes. Nevertheless, the technology remains in its early stages of development and requires substantial progress before widespread commercial availability is feasible.

A significant hurdle to the adoption of solid-state technology is the constraint on energy density achievable within the cathodes, measured per unit volume. Increasing cathode thickness appears to be a logical solution to this limitation.

However, increasing cathode thickness can compromise the battery’s mechanical and thermal integrity. This instability can manifest as delamination, cracking, and separation of components, ultimately leading to premature battery failure.

Furthermore, thicker cathodes impede the diffusion of ions and reduce overall power output. Consequently, a practical limit exists on cathode thickness, which in turn restricts the performance capabilities of the anodes.

Key Obstacles to Commercialization

• Cost reduction is crucial, particularly for the automotive sector aiming for aggressive targets like $50/kWh.
• Improving the manufacturing processes for solid-state batteries is essential.
• Balancing cathode thickness with mechanical stability and power output remains a significant engineering challenge.

Addressing these challenges is vital to unlocking the full potential of solid-state battery technology and realizing its widespread application.

Silicon Materials: Innovative Approaches

Currently, many companies focused on silicon battery development are incorporating silicon into graphite mixtures, typically up to 30%, to enhance energy density. Sila Nanotechnologies’ battery production serves as a prime example of this silicon-composite strategy. Alternatively, some manufacturers are exploring the use of 100% silicon anodes.

Employing pure silicon anodes, such as the method utilized by Amprius, can yield even greater energy density. However, this approach is constrained by the necessity for exceptionally thin electrodes and elevated manufacturing expenses.

Challenges with Silicon

Silicon offers a substantially improved energy density compared to traditional materials. A key obstacle hindering its widespread implementation has been the material’s tendency to expand and contract during charge and discharge cycles.

This volumetric change negatively impacts both battery lifespan and overall performance. Degradation problems stemming from this expansion and contraction must be addressed before widespread commercial use is feasible.

Current Commercial Applications

Despite these hurdles, silicon-based batteries are already seeing commercial deployment in select areas. The automotive industry, particularly in the realm of electric vehicles (EVs), is at the forefront of silicon adoption.

Tesla currently leads the charge in integrating silicon technology into its EV battery systems, demonstrating the growing viability of these advanced materials.

• Silicon-graphite composites are the most common approach.
• Pure silicon anodes offer higher density but are more expensive.
• Volume expansion remains a key challenge.

The Drive Towards Electrification Demands Innovative Battery Design

Significant progress in battery architecture and cell construction is paving the way for enhancements in both current and next-generation battery technologies.

A particularly noteworthy development, especially for the wider public, is Tesla’s innovative “biscuit tin” battery cell, first presented at their 2020 Battery Day. While still utilizing lithium-ion chemistry, the design incorporates a novel approach by eliminating the conventional tabs that serve as the positive and negative connectors between the anode and cathode, as well as the traditional battery casing.

Instead, a shingled arrangement is implemented within the cell itself. This alteration in design not only streamlines manufacturing processes and reduces associated costs but also extends driving range and mitigates thermal limitations often encountered during rapid DC fast-charging.

Another increasingly popular strategy within the industry involves a shift from conventional two-dimensional electrode structures to three-dimensional configurations. This 3D structure delivers both elevated energy and power output for all battery chemistries.

Currently undergoing research and testing, 3D electrodes have demonstrated a doubling of accessible capacity, a 50% reduction in charging duration, and a 150% increase in lifespan for high-performance applications, all while maintaining competitive pricing. Consequently, to fully realize the potential of energy storage across diverse applications, prioritizing the development of solutions focused on modifying the physical structure of batteries is essential.

Securing Dominance in the Battery Industry

Success in the battery industry won't solely depend on enhanced performance; mastering production techniques and minimizing costs are equally vital. Global expansion of the battery market, forecasted to attain $279.7 billion by 2027, necessitates that nations develop methods for large-scale, low-cost battery manufacturing to secure a substantial market share.

Emphasis should be placed on “drop-in” solutions and novel production processes that integrate seamlessly with current assembly lines and existing materials.

The Role of Government Initiatives

The American Jobs Plan, championed by the Biden administration, underscores the significance of domestic battery production for the United States to lead in electrification and meet aggressive carbon emission reduction goals.

Such commitments will be instrumental in determining which entities can sustain a crucial competitive advantage within the battery sector and capture the largest portion of the $162 billion worldwide electric vehicle (EV) market.

A Holistic Approach to Battery Technology

The technologies that ultimately prevail in the drive towards complete electrification will be those that deliver the greatest improvements in performance, reduce expenses, and ensure compatibility with established manufacturing systems.

A comprehensive strategy, concentrating on both innovative cell designs and the refinement of existing battery chemistries, is essential to achieve the next generation of battery performance and accelerate commercial deployment – a need that is globally pressing.