The demand for lithium-ion batteries (LIBs) with high mass-specific capacities, high rate capabilities and long-term cyclabilities is driving the research and development of LIBs with nickel-rich NMC (LiNi x Mn y Co 1−x−y O 2 , x ⩾ 0.5 ) cathodes and graphite (Li x C 6 ) anodes. Based on this, this review will summarize recently reported and widely recognized studies of the degradation mechanisms of Ni-rich NMC cathodes and graphite anodes. And with a broad collection of proposed mechanisms on both atomic and micrometer scales, this review can supplement previous degradation studies of Ni-rich NMC batteries. In addition, this review will categorize advanced mitigation strategies for both electrodes based on different modifications in which Ni-rich NMC cathode improvement strategies involve dopants, gradient layers, surface coatings, carbon matrixes and advanced synthesis methods, whereas graphite anode improvement strategies involve surface coatings, charge/discharge protocols and electrolyte volume estimations. Electrolyte components that can facilitate the stabilization of anodic solid electrolyte interfaces are also reviewed, and trade-offs between modification techniques as well as controversies are discussed for a deeper understanding of the mitigation strategies of Ni-rich NMC/graphite LIBs. Furthermore, this review will present various physical and electrochemical diagnostic tools that are vital in the elucidation of degradation mechanisms during operation to supplement future degradation studies. Finally, this review will summarize current research focuses and propose future research directions.

All-solid-state lithium metal battery is the most promising next-generation energy storage device. However, the low ionic conductivity of solid electrolytes and high interfacial impedance with electrode are the main factors to limit the development of all-solid-state batteries. In this work, a low resistance-integrated all-solid-state battery is designed with excellent electrochemical performance that applies the polyethylene oxide (PEO) with lithium bis(trifluoromethylsulphonyl)imide as both binder of cathode and matrix of composite electrolyte embedded with Li 7 La 3 Zr 2 O 12 (LLZO) nanowires (PLLN). The PEO in cathode and PLLN are fused at high temperature to form an integrated all-solid-state battery structure, which effectively strengthens the interface compatibility and stability between cathode and PLLN to guarantee high efficient ion transportation during long cycling. The LLZO nanowires uniformly distributed in PLLN can increase the ionic conductivity and mechanical strength of composite electrolyte efficiently, which induces the uniform deposition of lithium metal, thereby suppressing the lithium dendrite growth. The Li symmetric cells using PLLN can stably cycle for 1000 h without short circuit at 60 °C. The integrated LiFePO 4 /PLLN/Li batteries show excellent cycling stability at both 60 and 45 °C. The study proposed a novel and robust battery structure with outstanding electrochemical properties.

Chemically cross-linked cellulose nanocrystal aerogels represent a versatile and universal substrate on which to prepare lightweight hybrid materials. In situ incorporation of polypyrrole nanofibers, polypyrrole-coated carbon nanotubes, and manganese dioxide nanoparticles in the aerogels gives flexible 3D supercapacitor devices with excellent capacitance retention, low internal resistance, and fast charge-discharge rates.

Due to high energy density, low cost, and nontoxicity, lithium-sulfur (Li-S) batteries are considered as the most promising candidate to satisfy the requirement from the accelerated development of electric vehicles. However, Li-S batteries are subjected to lithium polysulfides (LiPSs) shuttling due to their high dissolution in liquid electrolyte, resulting in low columbic efficiency and poor cycling performance. Moreover, the Li metal as an indispensable anode of Li-S batteries shows serious safety issues derived from the lithium dendrite formation. The replacement of liquid electrolytes with solid-state electrolytes (SSEs) has been recognized as a fundamental approach to effectively address above problems. In this review, the progress on applying various classes of SSEs including gel, solid-state polymer, ceramic, and composite electrolytes to solve the issues of Li-S batteries is summarized. The specific capacity of Li-S batteries is effectively improved due to the suppression of LiPSs shuttling by SSEs, while the rate and cycling performance remain relatively poor owing to the limited ionic conductivity and high interfacial resistance. Designing smart electrode/electrolyte integrated architectures, enabling the high ionic transportation pathway and compatible electrode/electrolyte interface, may be an effective way to achieve high performance solid-state Li-S batteries. and strategies have been attempted to address the above main issues of Li-S batteries, including using sulfur host materials, [4] unique separators [5] and interlayer, [6] composite of electrolyte, [7] novel binders, [8] etc. However, these approaches can only solve problems to a certain extent. Some review papers have concluded and commented on above potential solutions. [9] Recently, solid-state electrolytes (SSEs) including gel, solid-state polymer, ceramic, and composite electrolytes are attracting increasing interest for application in Li-S batteries to fundamentally solve the issues of Li-S batteries caused by liquid electrolyte. Furthermore, nonflammable solid electrolytes would improve the safety performance of Li-S batteries remarkably. In the past few years, more and more research work focused on applying SSEs in Li-S batteries to solve the LiPSs dissolution. [10] Some review papers about Li-S batteries have also emphasized the significance of SSEs. However, until now, there are few review papers specially summarizing the progress and prospect of the solid-state Li-S batteries.This review aims to provide an overview of SSEs for addressing the major drawbacks of Li-S batteries, including the electrochemical reaction process of S cathode and its corresponding problems as well as traditional solutions, the recent research progress of solid-state Li-S batteries using gel, solidstate polymer, ceramic, and composite electrolytes, and strategies for overcoming the deficiencies of solid-state electrolytes such as low room-temperature ionic conductivity and high Solid-State Electrolytes interfacial resistance. In addtition, the mechanism a...

Polypyrrole-coated multiwalled carbon nanotubes (PPy-MWCNT) were used for the fabrication of activated carbon-coated MWCNT doped with nitrogen (N-AC-MWCNT). The conceptually new method for the fabrication of non-agglomerated PPy-MWCNT with good coating uniformity allowed the fabrication of uniform and welldispersed N-AC-MWCNT with high surface area. The use of N-AC-MWCNT allowed the fabrication of supercapacitor electrodes with high mass loading in the range of 15−35 mg cm −2 and with a high active material to current collector mass ratio of 0.21−0.50. The N-AC-MWCNT electrodes showed excellent electrochemical performance in aqueous 0.5 M Na 2 SO 4 electrolyte. The maximum specific capacitance of 3.6 F cm −2 (103.1 F g −1 ) was achieved for mass loading of 35 mg cm −2 at a scan rate of 2 mV s −1 . The aqueous supercapacitor cells, based on N-AC-MWCNT electrodes, exhibited excellent performance with energy density of 16.1 mWh g −1 , power density of 14.4 W g −1 , and enlarged voltage window of 1.8 V. The individual electrodes and cells showed good capacitance retention at high charge−discharge rates and good cycling stability. Moreover, the N-AC-MWCNT electrodes showed promising performance for capacitive deionization of water. The feasibility of capacitive removal of organic dyes from aqueous solutions has been demonstrated. A quartz crystal microbalance method was used as a tool for the analysis of electrosorption and electrodesorption of ions and charged dyes during charge and discharge.