A novel pre-lithiation strategy achieved by the capacitive adsorption in the cathode for lithium-ion capacitors

Pre-lithiation is a critical component to improve the performance of lithium-ion capacitors. However, the process of pre-lithiation may bring some safety problems or hazards for the capacitor itself, like the danger associated with the usage of metallic lithium or impairments of the cathode. In this work, a novel cathode pre-lithiation method is proposed to avoid those problems. In this strategy, lithium ions are stored in the cathode by capacitive adsorption in advance. And they are used as the lithium source to achieve the pre-lithiation in the first few cycles. Meanwhile, the degree of pre-lithiation can also be regulated by changing the charge voltage of the capacitive adsorption. The full LIC device pre-lithiated through this method has a specific capacity of 31.4 mAh g−1. In addition to providing potential solutions for hazards associated with metallic lithium or the performance of the cathode in the production of LICs, the study will also offer some insights through a new design of the cathode pre-lithiation method.