High-performance soft-packaged supercapacitors with high energy density enabled by advanced boron-modified single-walled carbon nanotubes-enhanced nickel oxide.

Soft-packaged supercapacitors (SCs) provide notable advantages, including high power density, high safety, and long lifespan, yet their application is still relatively limited due to the low energy density and insufficient cycle stability. To assess their practicality, we employed a simple in-situ nucleation assembly and high-temperature calcination strategy tofabricate boron-modified single-walled carbon nanotubes-enhanced nickel oxide (B-(NiO@SWNT)) electrodes, characterised by rich oxygen vacancies (O) and high specific surface area. The results demonstrated that the B-(NiO@SWNT) electrode provided a formidable specific capacitance of 1257.7F g at 1 A g, with excellent cycling stability (98.3 % retention over 10,000 cycles). Additionally, the B-(NiO@SWNT)//nitrogen-doped graphene (GN) device had an outstanding energy density (53.0 Wh kg at 900 W kg), surpassing many SCs reported to date. A soft-packaged SCs also showed robust electrochemical performance and was effective in powering electronic devices like smartphones and wearable technology, etc. This work offers a new perspective on the practical application of soft-packaged SCs in portable electronic products.