Astronauts aboard China's Tiangong space station have completed an experiment to study how microgravity affects the internal performance of lithium-ion batteries, according to the Chinese Academy of Sciences'Dalian Institute of Chemical Physics.

The institute announced on Wednesday that the Shenzhou XXI crew conducted the on-orbit operations together. Payload specialist Zhang Hongzhang utilized his professional expertise to lead the experiment's technical execution.

The project seeks to analyze the mechanisms through which microgravity influences key processes inside lithium-ion batteries. The institute said the research aims to provide "solid scientific evidence" to improve the efficiency of energy systems used in spacecraft.

Lithium-ion batteries are a critical power source for modern space missions due to their high energy density, long life cycle, and safety. Research has increasingly focused on microscopic mechanisms, specifically how the distribution of chemicals within the electrolyte affects battery power and service life.

In ground-based experiments, the gravitational field is constantly intertwined with the electric field.

This makes it difficult for researchers to isolate gravity's specific impact on internal battery processes. The microgravity environment of space allows scientists to study more "purely" processes such as ion transport, insertion, and extraction.

However, microgravity also presents challenges. The institute noted that liquid behavior inside batteries can differ significantly from that on Earth, leading to potential performance degradation and higher safety risks.

During the mission, Zhang conducted in situ optical observations and captured full-process images of lithium dendrite growth — microscopic, needlelike structures that can cause batteries to short-circuit. His tasks included monitoring the experiment in real time and recording key scientific phenomena.

The institute expects the experiment to help break the understanding bottleneck regarding coupled gravity and electric field effects, and provide a basis for optimizing current on-orbit systems and designing next-generation space batteries with increased energy capacity and safety.