High‐Performance Bioinspired Rechargeable Cement‐Based Batteries for Low‐Carbon Self‐Powered Buildings

Cement-based batteries (CEMBs) uniquely integrate energy storage and load-bearing functions, offering transformative potential for self-powered and sustainable buildings. Unfortunately, their application is greatly hindered by low capacity and limited cycle life. The high tortuosity of ion transport at the centimeter scale, and sluggish kinetics at the electrolyte/electrode interfaces in CEMBs are the two main reasons for the limited energy storage performance. Herein, these issues by designing vertically aligned pore channels in a cement matrix is overcome, mimicking the tracheid structure of conifer. This bioinspired design reduces the ion transport tortuosity from 7.80 to 2.86, resulting in a fourfold increase in ion conductivity (to 32.7 mS cm^-1), while maintaining high mechanical strength (41.6 MPa). The quasi-solid-state CEMBs demonstrate superior performance, delivering a remarkable capacity of 114 mAh g^-1 and retaining 63.2% of their capacity after 300 cycles at 0.5 A g^-1. In comparison, traditional CEMBs exhibit a lower initial capacity of 62 mAh g^-1 and experience rapid degradation, losing functionality after just 75 cycles. Impressively, the bioinspired CEMBs can simultaneously charge a mobile phone and endure external mechanical loads, showcasing their dual functionality. This innovative bioinspired design presents a promising pathway for scaling up cement-based energy storage systems to enable low-carbon, self-powered buildings.