Batteries as a Military Enabler
Batteries, often overlooked, could quietly tilt the balance of military power. Yes, it’s true. Batteries have military implications, creating difficult tradeoffs for policymakers balancing strategic, economic, and decarbonization priorities. While mainland China’s lithium-ion storage batteries are useful for meeting economic and decarbonization goals across the United States, Europe, and elsewhere, its battery complex poses potential security risks, especially in the event of a contingency over Taiwan.
Batteries are an increasingly important feature in military affairs, with use cases ranging from diesel-electric submarines to unmanned platforms and more. Moreover, synergies between China’s battery, drone, and shipbuilding complexes are alarming. There is, however, only limited recognition of batteries’ growing importance in military affairs, especially in a contingency over Taiwan. While positive steps are being taken to limit Beijing’s industrial and technological capacity in batteries, the Washington- and Brussels-led alliance system must act more vigorously.
To constrain China’s battery complex, the United States and its allies should continue to phase in tariffs on Chinese exports of lithium-ion batteries for grid storage and electric vehicles. Given the importance of reducing sole-supplier dependency risks, Washington and Brussels should work together to de-risk supply chains, especially in upstream mining and refining for raw materials like graphite, nickel, and lithium. Furthermore, the West should ensure that any battery technology transfers do not aid the Chinese defense industrial base — although, bluntly, Chinese batteries are often at the technological frontier.
In addition to limiting China’s battery complex, the free world, especially the United States, must strengthen itself by expanding its own battery capacity and capabilities. This will entail undertaking fiscal investments, reforming onerous permitting requirements, adopting new policy mechanisms, and incentivizing research and development.
These steps, taken in tandem, will reduce the probability that Beijing is the first to achieve technological breakthroughs for even more advanced batteries, such as solid-state batteries, that could deliver game-changing commercial applications and potential military uses.
To accelerate the development of the U.S. battery industry and its attendant strategic, economic, and environmental benefits, policymakers should reach a bipartisan agreement that streamlines reviews for all energy projects — including renewables, nuclear energy, mining for critical materials, and, yes, oil and gas development. Ensuring that the United States can build infrastructure quickly will strengthen the arsenal of democracy’s manufacturing capacity, deterring potential adversaries.
The disturbances from Russia’s invasion of Ukraine prove that energy security is national security. The Washington- and Brussels-led alliance system should strengthen internal manufacturing capacity, especially for critical dual-use technologies like batteries, while taking steps to constrain the technological and industrial capacity of the Chinese battery complex.
The Military Implications of China’s Battery Complex
China’s battery complex complements its military capabilities.
Consider aerial drones, especially one-way attack assets. These weapons already figure prominently in Russia’s invasion of Ukraine, with Samuel Bendett estimating that both combatants field at least 50,000 first-person-view suicide drones per month. Crucially, these one-way attack drones often use lithium-ion batteries for propulsion.
While lithium-ion–powered one-way attack drones are already revolutionizing warfare in Russia’s full-scale invasion of Ukraine, constraining daytime maneuver, unmanned aerial drones could play an even larger role in any confrontation over Taiwan. China’s output of potential dual-use drones dwarfs production seen in both Ukraine and Russia. A single Chinese dronemaker, DJI, holds a 90 percent share of the global consumer drone market. While military and civilian drones have different roles and capabilities, China could repurpose civilian drone production lines for the needs of its armed forces, just as it would use its civilian shipbuilding yards to repair its naval fleet during wartime. Mainland China’s industrial capacity in aerial drones and batteries, along with its proximity to Taiwan, could prove significant in a confrontation.
Still, there will be limitations to the role batteries can play in the aerial domain. Owing to its greater energy density, gasoline stores vastly more power than batteries for the same weight. As Justin Bronk and Jack Watling write for the think tank RUSI, “For applications requiring light payloads over short ranges for limited periods, electrical power is generally the preferred solution, while the longer the required range and the heavier the payload, the more compelling combustion engines powered by fuels become.”
Additionally, the Taiwan Strait has high wind speeds most of the year (summer is an important exception) that would buffet smaller platforms and likely make them inoperable. Finally, and significantly, most first-person-view drones have a limited range of about five to 20 kilometers, not nearly enough to range Taiwan from mainland China without adjustments that add technical complexity and cost.
Batteries will therefore play an important — but probably constrained — role in China’s aerial drone fleet. Still, battery technology breakthroughs, especially improvements in energy density, could increase the saliency of aerial drones in the event of a contingency over Taiwan.
Worryingly, there are indications that the Chinese navy is expanding aerial drone use in operations. China recently launched the world’s first dedicated drone carrier and has constructed at least two drone motherships. Analysts believe these platforms are being used for training purposes, especially to simulate hostile drone swarms. Accordingly, the Chinese navy appears to be in the early days of employing drone swarm capabilities. Many, probably most, of these drones will be fueled by gasoline, diesel, or jet fuel, but expendable lithium-ion battery–powered drones could also play a role. Synergies between China’s aerial dronemaking capabilities, shipbuilding prowess, and its battery complex should be a focus of coalition military planners.
Batteries are likely to prove even more significant for the maritime domain, which will be a critical feature in any confrontation over Taiwan.
Batteries are employed in unmanned underwater vessels, unmanned surface vessels and, non-nuclear-powered submarines. Most navies, especially those without access to nuclear-powered vessels, operate diesel-electric submarines with propulsion batteries charged via diesel generation. With existing lead-acid batteries, diesel-electric subs must frequently rise near the surface to intake air, or snorkel, which allows them to clear diesel exhaust and recharge batteries for operation but raises the risk of detection.
Lithium-ion battery–powered submarines offer performance improvements over existing lead-acid batteries. Some benefits of lithium-ion batteries include lower risk of detection (due to less need for snorkeling, as well as quieter operations), longer underwater endurance, and higher speeds for sprinting and cruising. Japan’s is the only navy confirmed to operate diesel-electric submarines with lithium-ion batteries.
Other navies could soon employ submarines with lithium-ion batteries. Although the United States does not currently operate diesel-electric submarines itself, there may be synergies with not only Japanese but also South Korean shipyards. But the People’s Republic of China looms large. Although the Chinese system is generally better at implementation than innovation, its battery complex has made undeniable advances in recent years and is in many ways more technologically advanced than the global West’s. China’s navy could field advanced lithium-ion diesel-electric submarines over the medium term and may already have plans to do so.
Solid-state batteries offer even greater capabilities than lithium-ion batteries, including greater energy density, capacity, and range. Crucially, solid-state batteries are advantaged over lithium-ion batteries at preventing fires, which are a major risk aboard submarines. While solid-state batteries have yet to be commercialized due to cost and technical challenges, military customers — including in China — are not as price-sensitive. The development of solid-state batteries could therefore offer substantial performance improvements for both diesel-electric submarines and unmanned systems below, on, and above the surface.
Washington’s Battery Balancing Act: Recommendations
The larger and more sophisticated the Chinese battery complex becomes, the more likely it is to secure technological advances in next-generation solid-state batteries that could revolutionize energy or transform military affairs. It could also leverage its existing industrial capabilities in lithium-ion batteries to scale deployments of unmanned and manned aerial and maritime systems. Accordingly, the Washington- and Brussels-led democracies should work jointly to limit the Chinese battery complex by phasing in tariffs. At the same time, they must also develop their own industrial base and technological capacity.
Critics of tariffs on Chinese products claim that these measures would raise battery costs and slow decarbonization efforts without alleviating dependency on Chinese-made batteries. Yet this criticism overlooks the fact that substantial progress has already been made in building out the Western battery industrial base.
U.S. investment in batteries has surged since the passage of the Inflation Reduction Act in August 2022. Cumulative investments from the fourth quarter of 2022 to the first quarter of 2024 totaled $42.2 billion. According to the Clean Investment Montor, batteries investment in the first quarter of this year stood at $11.4 billion, an all-time high and 486 percent higher than the same period in 2022. Nor are commercial battery advances limited to the United States, as Japanese company TDK recently announced a breakthrough that will allow it to expand energy density at 100 times that of current levels. Applying tariffs to Chinese-made batteries creates a void that Western manufacturers can fill.
Developing a Western “battery industrial base” will require a reliable supply chain. The United States and critical coalitional partners — especially South Korea, Japan, Australia, Canada, and Taiwan — should aim to rapidly de-risk potential supply chain chokepoints, as Beijing’s October 2023 graphite restrictions demonstrate it will continue to try to exploit any vulnerabilities. Otherwise, shortfalls in extracting and refining battery metals could strangle the coalition’s battery supply chain, as a recent Foreign Affairs article shows. To address supply chain risks, policymakers should adopt creative mechanisms, such as creating new benchmarks, financing hedging instruments, establishing price insurance, and maintaining strategic reserves.
Forging a reliable batteries supply chain will necessitate working with allies and partners across a variety of different commodities in the mining sector. For instance, graphite reserves are concentrated in Turkey and Brazil; Indonesia and Australia hold the world’s largest reserves of nickel.
Additionally, China is increasingly outpacing the United States and others in research and development in the applied physical sciences — including in materials science, chemistry, and engineering. Accordingly, the United States and others should respond by expanding investments in these sectors, which will likely deliver a positive return on investment. Importantly, these efforts could garner bipartisan support, as the potentially transformational Endless Frontiers Act enjoyed the support of Republican and Democratic senators.
In addition to de-risking supply chains and supporting research and development, Washington and Brussels should accelerate indigenous energy deployment. Streamlining procedures for the permitting of electricity generation assets, transmission lines, mining and refining, and electric vehicle charging infrastructure would remove barriers holding back the West’s battery complex and its energy security. Given the stakes of the competition with Beijing, policymakers should be able to reach a bipartisan agreement that streamlines reviews for all energy projects, whether they are clean energy projects or conventional hydrocarbons. Expanding Western energy production is critical not only for energy security, but also for winning other energy-related competitions with Beijing, including in AI.
Finally, given batteries’ potential military applications, the West should closely examine its sectoral technology transfer policies. China’s battery complex frankly enjoys a technological edge in many respects. Still, the West’s leading battery powers should ensure that they are able to prevent tech leakage to China of cutting-edge technologies — especially solid-state batteries — that have substantial military applications, transformational commercial potential, or both.
At the same time, it’s important to stress that competition with Beijing should be managed responsibly. The West should continue to de-risk supply chains, especially for technologies with potential dual-use applications such as shipbuilding, dronemaking, and batteries. Yet it should also underscore that it does not seek to decouple from China entirely, nor does it seek unnecessary confrontation or conflict. There are hard limits to Western-Chinese ties; trade will not deliver a fundamental breakthrough in relations with Beijing. Still, commercial ties in non-sensitive areas mitigate security dilemmas, provide economic benefits, and, most importantly, limit the probability and consequences of an unnecessary and potentially catastrophic war between great powers.
Balancing deterrence and reassurance vis-à-vis Beijing is no easy task. That is especially true regarding trade in technologies, such as batteries, that deliver clear economic and environmental benefits, yet also have latent or actual military potential. While Washington and Brussels should carefully manage competition with Beijing, they must also constrain China’s technological and industrial capacities, especially for critical products such as batteries, while ensuring that the coalition develops its own robust capabilities.
Joseph Webster is a senior fellow at the Atlantic Council’s Global Energy Center and Indo-Pacific Security Initiative and editor of the independent China-Russia Report. This article represents his own personal opinions.
