Integrated Thin Film Battery Design for Flexible Lithium Ion Storage: Optimizing the Compatibility of the Current Collector‐Free Electrodes

Abstract

The design of flexible full-cell configuration relies on the light-weight arrangement, structural robustness, compositional compatibility, and shape conformability of the coherent components. In this article, a general and scalable spin-coating approach is developed to integrate the flexible, current-collector-free cathode and anode in the thin film batteries with the layer-stacked configuration. The design of the ternary composite anode involves the reduced graphene oxide encapsulation of the MoS 2 /N-doped carbon microrods composite (rGO-MoS 2 / NC) via the facile hydrothermal-calcination process. In the similar structure design of the cathode, the ball-milled nanocrystalline mixture of LiMn 2 O 4 and LiVPO 4 F is wrapped within the GO interfacial protection layer. Furthermore, the slurries of electroactive materials with the predetermined areal capacity ratio of negative to positive electrodes (N/P ratio) are cast onto both sides of the nano-SiO 2 modified polyethylene (SiO 2 -MPE) separator via the facile spincoating process. The prototype full-cell configuration delivers a high reversible capacity, satisfactory capacity retention at the high rate, as well as good cyclability under different mechanical loadings. This integrated thin film battery model showcases its potential use in the flexible electronic devices.

Grafted MXenes Based Electrolytes for 5V‐Class Solid‐State Batteries

“…[19] Common flexible LIBs assembled with the conventional sandwich-stacked configuration exhibit inferior mechanical stability and reliability, which can be attribute to the simple physical contact between stacked layers that is not only less beneficial for the effective and sustained load transfer, but also causes inherently severe interlayer slippage and irreversible deformations in practical applications. [20,21] Flexible solid LIBs with all-in-one integrated architecture are promising for solving the above issues, because the continuous interface-less design can ensure efficient electron and/or load-transfer capability and avoid the relative displacement/detachment between the neighboring components of LIBs. [22] So far, 5 V-class flexible solid LIBs has never been reported.…”

Graphene‐Based Nanomaterials for Flexible and Stretchable Batteries

“…[20][21][22][23] Moreover, the weight of heavy metallic current collectors and the additives that are required in the slurry process negatively affects the gravimetric capacity. [23][24][25] Therefore, in order to develop a large-capacity flexible battery by avoiding problematic current collectors or the slurry-based process, many recent studies and developments have been conducted in numerous battery research fields such as in lithium-ion batteries (LIBs), [23,[26][27][28][29][30][31][32][33][34] sodium-ion batteries (SIBs), [35][36][37][38][39] other Recently, as flexible and wearable electronic devices have become widely popular, research on light weight and large-capacity batteries suitable for powering such devices has been actively conducted. In particular, graphene has attracted considerable attention from researchers in the battery field owing to its good mechanical properties and its applicability in various processes to fabricate electrodes for batteries.…”

A High-Energy 5 V-Class Flexible Lithium-Ion Battery Endowed by Laser-Drilled Flexible Integrated Graphite Film

“…Recently, various electrochemical energy storage systems, including the most widely used rechargeable lithium-ion batteries (LIBs), are rapidly entering their era of “flexibility” because of the increasing requirement of flexible/wearable electronics. − As for flexible LIBs, great efforts have been focused on the evolution of flexible electrodes using carbon nanomaterials (such as graphene, carbon nanofibers (CNFs), carbon nanotubes (CNTs), etc.) as a nonmetal current collector. ,,− ,− Unfortunately, the mass production and processability of these flexible electrode films using carbon nanomaterials as the nonmetal current collector are still challenging, constraining the rapid commercialization process of flexible LIBs in a way. , Undoubtedly, future flexible LIBs are required to satisfy the consumers’ ever-growing high-energy demand on power sources for flexible/wearable electronics.…”

“…Recently, various electrochemical energy storage systems, including the most widely used rechargeable lithium-ion batteries (LIBs), are rapidly entering their era of “flexibility” because of the increasing requirement of flexible/wearable electronics. − As for flexible LIBs, great efforts have been focused on the evolution of flexible electrodes using carbon nanomaterials (such as graphene, carbon nanofibers (CNFs), carbon nanotubes (CNTs), etc.) as a nonmetal current collector. ,,− ,− Unfortunately, the mass production and processability of these flexible electrode films using carbon nanomaterials as the nonmetal current collector are still challenging, constraining the rapid commercialization process of flexible LIBs in a way. , Undoubtedly, future flexible LIBs are required to satisfy the consumers’ ever-growing high-energy demand on power sources for flexible/wearable electronics. However, most of the previously reported flexible LIBs (full cell) have suffered from low energy density due to the limitation of the flexible anode based on lithium titanate oxide (Li 4 Ti 5 O 12 , with a low capacity of ∼175 mAh g –1 and a high-voltage plateau at ∼1.5 V vs Li + /Li) and the lack of flexible integrated anode based on conventional graphite materials (with a high capacity of ∼370 mAh g –1 and a low average operating voltage at ∼0.1 V vs Li + /Li). ,− It is noted here that the fabrication of the self-standing flexible integrated graphite anode using carbon nanomaterials as the nonmetal current collector (without a Cu foil current collector) is still full of challenges, possibly due to the microscale particle size. ,− …”