Use of carbon and AlPO4 dual coating on H2Ti12O25 anode for high stability hybrid supercapacitor

High Lithium Insertion Voltage Single‐Crystal H2Ti12O25 Nanorods as a High‐Capacity and High‐Rate Lithium‐Ion Battery Anode Material

“…25 show similarC Vc urves.W elldefined redox peaks at potentials of approximately 1.5 (cathodic reduction)a nd 1.7 V( anodic oxidation) can be observed, and they correspond to the reduction/oxidation reactiono f H 2 Ti 12 O 25 during the lithiation/delithiation process. [13] Despite the fact that similar redox peaks are observed in the CV curves, there is ad ifference in the electrode reversibility.S uch reversibility can be compared by the difference (DE OR )b etween the oxidation and reduction potentials( E O ÀE R ), which are graphed in Figure 9c 25 .T his is similar to that reported in the literature, [37,38] whereby there is as trongd e- pendence of the capacity on the Li + -ion diffusionr ate. Althought he anodic and cathodic peak heights showaslightly downward trend with cycling, the CV curveso fb oth samples overlap well, which implies excellent cycling stability.T he above conclusion is in good accordancew ith the discharge/ charge resultsi nF igure 7.…”

“…However,t he chargec apacitieso fb oth m-H 2 Ti 12 O 25 and s-H 2 Ti 12 O 25 are low in the initial dozens of cycles, even though they both increases lowly to higher capacity.T he low initial capacity,w hich occurs only at high current densities, may be relatedt ot he sluggish solid-state diffusion process of Li + ions in the one-dimensional channels of H 2 Ti 12 O 25 . [13,36] Thus, at ah igh current density (lots of Li + simultaneously inserted into the H 2 Ti 12 O 25 crystal), if al arge amount of Li + ions with ar adius larger than that of H + quickly pours into the tunnel, poor diffusion of the Li + ions in the narrow one-dimensional tunnels will inevitably impede subsequentL i + diffusion toward the thermodynamically favorable interstices. However, after dozens of cycles,t he tunnel space has been expandeds tep by step, which hence leads to sufficient channel space for Li + -ion mobility.A saresult, the chargec apacitieso f m-H 2 Ti 12 O 25 and s-H 2 Ti 12 O 25 gradually increase, and the coulombic efficiencies are close to 100 %.…”

“…To enhancei ts electrochemical performance, control of the crystal orientation and morphologyi sa ne ffective wayt oc ope with slow Li + -ion diffusioni nside H 2 Ti 12 O 25 with severe anisotropy.I nt his report, Na 2 Ti 6 O 13 nanorods, prepared from Na 2 CO 3 and anatase TiO 2 in molten NaCl medium, were used as ap recursor in the synthesis of long single-crystal H 2 O 25 shows an outstanding theoretical capacity of 274.6 mAh g À1 , higher protonic conductivity of 8.71 10 À9 Scm À1 , [12] and better cycle performance. [10,13] In addition, the low exothermic behavior of H 2 Ti 12 O 25 also guarantees safety and thermals tability. [14,15] These outstanding features are conducive in promoting the application of H 2 Ti 12 O 25 as al ithium-ion battery anode to power hybrid electric vehicles.…”

Hierarchical ultrathin NiAl layered double hydroxide nanosheet arrays on carbon nanotube paper as advanced hybrid electrode for high performance hybrid capacitors

“…Recently, a hybrid supercapacitor (HSC), which is commonly composed of a battery-type electrode and a capacitive electrode, has been extensively investigated [10,11]. In this case, a wider operating voltage can be achieved, which leads to a higher energy density [12,13].…”

Binder- and conductive additive-free laser-induced graphene/LiNi1/3Mn1/3Co1/3O2 for advanced hybrid supercapacitors

“…In contrast, supercapacitors, also known as electrical double-layer capacitors, can facilitate fast charge transport, owing to their excellent power density (<15 kW/kg). The opinion that the future of electric vehicles (EVs) depend on supercapacitors rather than LIBs was suggested by Elon Musk in 2011 5 . However, supercapacitors have also suffered from a low energy density (<10 Wh/kg) in practical applications, as summarized in Table 1 6 .…”