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Compared with other commercial cathode materials, the LiNi0.8Co0.1Mn0.1O2 cathode (NCM811) has high specific capacity and a relatively low cost. Nevertheless, the higher nickel content in NCM811 leads to an extremely unstable interface between the electrode and the electrolyte, resulting in inferior cyclic stability of the corresponding cell. Use of film-forming additives is regarded as the most feasible and economic approach to construct a stable interface on the NCM811 cathode. However, less effective electrolyte additives have been reported to date. Herein, we propose a valid film-forming electrolyte additive, 2,4,6-triphenyl boroxine (TPBX), for application in a high-voltage NCM811 cathode. Experimental and computational results reveal that the TPBX additive can be preferentially oxidized to generate a highly stable and conductive cathode electrolyte interface (CEI) layer on the NCM811 cathode, which efficiently suppresses the detrimental side reaction and improves the electrochemical performance eventually. In detail, the cyclic stability of the Li/NCM811 half-cell is enhanced from 57% (without additive) to 78% (with 5% TPBX) after 200 cycles at 1C between 3.0 and 4.35 V. At a high current rate of 15C, the TPBX-containing electrode delivers a capacity of about 135 mAh g-1, which is much higher than that of the electrode without the additive (80 mAh g-1). Interestingly, the TPBX is also reduced earlier than the ethylene carbonate (EC) solvent to form an ionically conductive solid electrolyte interface (SEI) film on the graphite anode. Due to the CEI layer on the cathode and the SEI film on the anode simultaneously formed by the TPBX additive, the cyclic performance of the graphite/LiNi0.8Co0.1Mn0.1O2 full cell is enhanced. Therefore, the incorporation of the TPBX additive into the electrolyte provides a convenient method for the commercial application of the high-energy-density NCM811 cathode in high-voltage lithium-ion batteries.

High voltage LiNi0.5Mn1.5O4 material is a promising cathode for lithium ion battery, but the unsatisfied cycle stability hinders its further development in higher energy density battery. Amorphous terpolymer poly(butyl methacrylate-acrylonitrile-styrene) (P(BMA-AN-St)), which possesses good affinity with carbonated liquid electrolyte and high adhesion ability, is used together with traditional poly(vinylidene fluoride) (PVDF) binder to improve the cyclic performance of LiNi0.5Mn1.5O4 cathode. The retention ability of discharge capacity is 92% for Li/LiNi0.5Mn1.5O4 coin cell after 300 cycles at 1C rate when the cathode uses the co-binders of PVDF and P(BMA-AN-St) (2:1 in weight), compared with 55% capacity retention for the cathode fabricated with PVDF binder alone. From the physical and electrochemical characterizations of the cycled electrode, it is found that the introduced terpolymer enhances the liquid electrolyte uptake ability of LiNi0.5Mn1.5O4 cathode and the adhesion strength inside the particles by building a better interconnected conductive structure. Furthermore, the improved cycle stability of co-binder based cathode is contributed to the passivating layer formed by the terpolymer on the surface of LiNi0.5Mn1.5O4 particles, which effectively suppresses the decomposition of liquid electrolyte at high voltage and maintains the structural integrity of active material in the repeated intercalation/de-intercalation process.

Compared with other commercial cathode materials, the LiNi

Microbial fuel cells (MFCs) are attractive because they can harvest energy from sewage, but challenge remains in achieving valuable power density. To address this issue, we develop a novel binder-free anode, Nano-Fe3C@2D-NC@CC, by assembling 2D Zn-Fe-MOF arrays on the fibers of carbon cloth and subsequently carbonizing MOF. This fabrication results in a unique configuration that nano-Fe3C particles are highly dispersed on N-doped carbon arrays vertically standing on carbon fibers. The standing 2D arrays not only benefit bacterial adhesion but also guarantee nano-Fe3C particles with abundant sites for the charge transfer between bacteria and anode. Consequently, a superior power density (1606 ± 52 mW m−2) is harvested when the resultant Nano-Fe3C@2D-NC@CC is evaluated as the anode in MFCs based on a mixed bacterium culture. The facile fabrication of Nano-Fe3C@2D-NC@CC paves a promising path for the application of MFCs in large scale.

An array of single-walled carbon nanotubes (SWCNTs) coated with photoelectro-polymerized bisphenol A (PBPA) films is first fabricated using visible light-assisted multiple voltammetry. The PBPA layers endow the highly ordered SWCNTs@PBPA with unique photoelectrochemical and photoelectrocatalytic properties. A pair of well-defined redox peaks appears at the formal potential of − 0.165 V (vs. SCE) for the SWCNTs@PBPA-based electrode, which shows a linearly increasing photocurrent response with increasing BPA concentration. Furthermore, the presence of PBPA on SWCNTs leads to a negative shift of 0.158 V for the oxidative peak potential of 0.05 mM ascorbate under light irradiation, and a positive shift of 0.468 V or 0.412 V for the reduction peak potential of O2 or H2O2, respectively. The SWCNTs@PBPA arrays show good catalytic activities towards the oxidation of ascorbate and the reduction of O2. While simultaneously employing SWCNTs@PBPA as photoanode and cathode catalysts, the assembled ascorbate/O2 fuel cell exhibits remarkably enhanced performances. The proposed fuel cell indicates open-circuit photovoltage of 0.693 V, short-circuit photocurrent density of 0.29 mA cm− 2 and maximum power density of 14.05 μW cm− 2 upon light illumination of 0.18 mW cm− 2 visible light.