Direct Solar‐to‐Electrochemical Energy Storage in a Functionalized Covalent Organic Framework

Abstract

A covalent organic framework integrating naphthalenediimide and triphenylamine units (NT-COF) is presented. Two-dimensional porous nanosheets are packed with a high specific surface area of 1276 m g . Photo/electrochemical measurements reveal the ultrahigh efficient intramolecular charge transfer from the TPA to the NDI and the highly reversible electrochemical reaction in NT-COF. There is a synergetic effect in NT-COF between the reversible electrochemical reaction and intramolecular charge transfer with enhanced solar energy efficiency and an accelerated electrochemical reaction. This synergetic mechanism provides the key basis for direct solar-to-electrochemical energy conversion/storage. With the NT-COF as the cathode materials, a solar Li-ion battery is realized with decreased charge voltage (by 0.5 V), increased discharge voltage (by 0.5 V), and extra 38.7 % battery efficiency.

Integrated Photo‐Responsive Batteries for Solar Energy Harnessing: Recent Advances, Challenges, and Opportunities

“…More recently, Lv et al. employed a two‐dimensional porous covalent organic framework (NT‐COF) as the photocathode material to fabricate a solar‐driven LIB, which can enable photo‐responsive charge and discharge . The designed photoactive and electroactive NT‐COF composed by naphthalenediimide (NDI) and triphenylamine (TPA) units exhibited quick intramolecular charge transfer as well as extremely reversible electrochemical reaction.…”

“…Thus, in order to achieve high‐efficiency photo‐responsive batteries, internal integration of photo‐responsive functionalities into batteries with a two‐electrode configuration is undoubtedly a potential solution and have attracted increasing interest more recently . An integrated two‐electrode battery with excellent photo‐responsiveness allows for direct conversion/storage of the captured solar energy and relieves the energy density concern of the battery . In general, the traditional rechargeable cells possess many various types such as Li‐ion batteries, Li−S batteries, Li−O 2 batteries etc, which are built on different working principles.…”

Isostructural Three‐Dimensional Covalent Organic Frameworks

“…[1] Owing to their tunable structures and high porosity,COFs have gained great interest and shown promising applications in molecule storage and separation, [2] heterogeneous catalysis, [3] sensing, [4] energy storage, [5] and optoelectronics. [1] Owing to their tunable structures and high porosity,COFs have gained great interest and shown promising applications in molecule storage and separation, [2] heterogeneous catalysis, [3] sensing, [4] energy storage, [5] and optoelectronics.…”

Tactile UV‐ and Solar‐Light Multi‐Sensing Rechargeable Batteries with Smart Self‐Conditioned Charge and Discharge

“…Equipping conventional energy devices with various stimuli is a good solution to fulfilling multiple smart functions such as self‐powered electronics/optoelectronics/sensors. In this regard, some advances were achieved by imparting some functions such as electrochromics, shape‐memory, thermal, or light effects– into supercapacitors or Li ion or Na/Br 2 batteries. Unluckily, a majority of reported responsive systems are based on single stimulus response and suffer from either unsatisfactory energy density, or complicate fabrication procedure, or rigorous design requirement caused by inevitable safety issues, which greatly limit their application scopes .…”