Cryogenic Joule-Heating Engineered Acetylene Black for Stable Conductive Domains in Long-Life Lithium-Ion Batteries

The mechanical stability of lithium-ion battery (LIB) electrodes is often compromised by volumetric changes during cycling, significantly reducing their long-cycle performance. Conventional conductive carbon blacks, such as Super P, face limitations in terms of high energy consumption, long synthesis times, and difficulty in achieving precise structural control. In this study, we develop a novel cryogenic Joule-heating technique to transform conventional acetylene black to zigzag-structured acetylene black (ZSAB). This unique architecture imparts enhanced surface roughness to ZSAB, improving its bonding with the binder and creating a more stable and efficient conductive network. As a result, ZSAB demonstrates exceptional cycling stability, retaining 95.5% of its capacity after 320 cycles at 0.5 C in LiFePO4 cathodes, outperforming Super P, which retains only 92%. Furthermore, when incorporated as a conductive additive in silicon–carbon anodes, ZSAB enhances the reversible capacity to 702 mAh g–1 after 50 cycles at 1 A·g–1, a substantial improvement compared to the 134 mAh g–1 achieved with Super P. This work offers new insights into the design of high-performance conductive agents for LIBs, highlighting the potential of cryogenically engineered acetylene black for enhanced battery longevity and performance.