Pre‐Lithiation Strategies for Lithium Ion Capacitors: Past, Present, and Future

Abstract

Lithium ion capacitor (LIC) is an emerging technology that holds promise to bridge the energy‐to‐power gap between already market stablished lithium ion battery and electrochemical double‐layer capacitor technologies. Academic research is mainly focused on increasing energy, power and cycle life metrics, but next, pre‐lithiation strategy is the key that will open the final door, or not, towards industrialization and commercialization of the technology. Its relevance has only recently been thoroughly considered, but several strategies, all with their own particular set of assets, are already available within the state‐of‐the‐art. It is the right moment to make a retrospective review analysis of the pros and cons of each of the strategies, in order to draw the correct conclusions and look into the future with the best perspective. Despite some reviews newly considered the topic, they were all done in a broader framework, what finally waters down the importance of this critical step. Thus, this review aims to solely focus on the pre‐lithiation strategies that have been reported so far for LICs, from the first academic auxiliary lithium metal approach to the latest novel strategies. To conclude, challenges and requierements that the ideal pre‐lithiation strategy should fulfil in order to foster market uptake of LIC technology are also discussed.

The Advance and Perspective on Electrode Materials for Metal–Ion Hybrid Capacitors

“…Prelithiation/presodiation/prepotassiation will reduce the potential of the anode, increase the potential of the cathode, and expand the potential window of the cell, achieving higher energy density, higher power output, and longer cycling lifespan. [ 174 ]…”

“…[ 6 ] Numerous novel types of sacrificial matters, such as Li 6 CoO 4 , Li 3 N, and Li 2 S, have been reported to improve the performance of MHCs. [ 128,174 ] Similar to the role of sacrificial organic lithium salt, functional organic sodium salts can be used to compensate for the initial irreversible ion consumption. A voltage‐induced in situ presodiation method was proposed to supply a sufficient sodium source to the cathode via an organic sodium salt (Na 2 C 6 O 6 ).…”

Microstructured nitrogen-doped graphene-Sn composites as a negative electrode for high performance lithium-ion hybrid supercapacitors

“…Prior to LIC assembly rGO800-N and rGO800-N-Sn were pre-lithiated to form the SEI and supply enough lithium to balance the rst cycle irreversibility. 39 Briey, electrodes were cycled between 0.002 and 2 V vs. Li/Li + at C/10 using an auxiliary Li electrode. Then, a cut-off potential of 0.2 V vs. Li/Li + was set to maximize the use of the negative electrode and prevent lithium plating.…”

Unraveling the Technology behind the Frontrunner LIC ULTIMO to Serve as a Guideline for Optimum Lithium‐Ion Capacitor Design, Assembly, and Characterization

“…Pre-lithiation is currently the barrier to overcome for market success of this technology and it needs to be addressed both from the scientific point of view but also from the technical implementation side. [34,35] Despite the challenge, or maybe, because of the great challenge it represents, very little academic research is focused on the topic. Carbons, the dominant materials in the field, not being a natural source of lithium, they lack an internal source to compensate for the first cycle irreversibility without depleting the lithium content in the electrolyte, thus compromising performance and cycle life.…”