Suggested Citation:
Zhao, Jingyuan, Yunhong Che, Yuqi Li, Hao Jing, Shiqi Ou, Daniel Sperling (2026)

Trade-Offs in Battery Integration for Transportation

Battery integration in automotive applications has evolved from conventional cell-to-module architectures to cell-to-pack, cell-to-chassis and cell-to-body configurations. By removing module-level boundaries and embedding electrical, thermal and mechanical functions into shared structures, integrated designs have enabled system-level volumetric efficiencies above 70% and energy densities approaching 255 Wh kg⁻¹ while also enhancing vehicle-level torsional stiffness. In this Perspective, we examine how structural battery integration reshapes safety, economic and governance trade-offs across the battery life cycle, focusing on automotive systems while highlighting broader implications for battery-integrated applications with tightly coupled architectures. Integration introduces three fundamental tensions: efficiency versus safety, architectural compactness versus life-cycle recoverability, and design flexibility versus regulatory compliance. Although integration could reduce component count and manufacturing cost, these gains can be difficult to retain when diagnostic access narrows, intervention shifts from module-level repair to pack-level replacement and disassembly-dependent material recovery declines. These trade-offs render the benefits of structural integration conditional on the alignment of safety, economic and regulatory considerations. To evaluate these interdependent trade-offs, we outline a system-level evaluation framework spanning engineering, diagnostic and governance domains to inform life-cycle-aware battery integration.