3D-printed highly deformable electrodes for flexible lithium ion batteries

Flexible and stretchable batteries are the essential energy storage system to power wearable and epidermal electronics. A key component in flexible batteries is deformable electrodes that can sustain large and repeated stretches and maintain satisfactory electrochemical performance. Existing solutions to deformable electrodes often involve complex fabrication approaches, leading to high cost and thus limiting their widespread use. It is highly desirable to fabricate high performance deformable electrodes via a low-cost manufacturing approach. Here, we report 3D-printed LFP/LTO electrodes with satisfactory electrochemical performance and mechanical durability under large and repeated stretches. We show that, after 100 stretch-release cycles, 92% and 88% capacity retention could be obtained for the half cells with the suitably patterned and printed LFP cathode and LTO anode during 100 discharge/charge cycles. More importantly, a pouch cell battery with the suitably patterned and printed LFP/LTO electrodes exhibit a high discharge capacity of around 120 ​mAh g⁻¹ at 0.3 ​C, as well as remarkable deformability. The facile 3D printing of the suitably patterned electrodes leads to low-cost manufacturing of high performance deformable electrodes, demonstrating the promising potential of such printed electrodes to enable stretchable and flexible energy storage devices to be used in soft robotics, wearable, and bio-integrated electronics.