Novel active management of compressive pressure on a lithium-ion battery using a phase transition actuator

Abstract

This study proposes a novel method for managing the compressive pressure imposed on a lithium-ion battery (LIB) using a phase transition actuator under constrained conditions considering the influence of compressive pressure on the performance and lifespan of LIBs. Specifically, an active pressure management strategy is proposed to maintain the optimal pressure and reduce the equivalent impedance during operation. A closed-loop control scheme is used to maintain compressive pressure via a phase transition actuator considering the dynamic characteristics of the actuator. This configuration allows managing both reversible pressure due to phase transitions at lithium intercalation/deintercalation and irreversible pressure evolution due to solid–electrolyte interface formation and growth. The analysis on experiments indicates that the equivalent impedance and capacity can be managed through active pressure management under stationary and stochastic operational conditions, demonstrating the effectiveness of the proposed method. Specifically, the accumulated stress in an LIB caused by pressure variation is reduced by 56.17% under a stochastic load condition when activating the proposed pressure management strategy, resulting in a 1.47% increase in discharge capacity immediately after operation compared to that under a passive pressurized condition. The proposed method is simple, effective, and economically feasible for battery management systems in terms of compression pressure control.