  Cobalt carbonate hydroxide (CCH) is a pseudocapacitive material with
remarkably high capacitance and cycle stability. Previously, it was reported
that CCH pseudocapacitive materials are orthorhombic in nature. Recent
structural characterization has revealed that they are hexagonal in nature;
however, their H positions still remain unclear. In this work, we carried out
first-principles simulations to identify the H positions. Through the
simulations, we could consider various fundamental deprotonation reactions
inside the crystal and computationally evaluate the electromotive forces (EMF)
of the deprotonation ($V_\mathrm{dp}$). Compared with the experimental
potential window of the reaction ($< 0.6$ V (vs. saturated calomel electrode
(SCE))), the computed $V_\mathrm{dp}$ (vs. SCE) value ($3.05$ V) was beyond the
potential window, indicating that deprotonation never occurred inside the
crystal. This may be attributed to the strongly formed hydrogen-bonds (H-bonds)
in the crystal, thereby leading to the structural stabilization. We further
investigated the crystal anisotropy in an actual capacitive material by
considering the growth mechanism of the CCH crystal. By associating our X-ray
diffraction (XRD) peak simulations with experimental structural analysis, we
found that the H-bonds formed between CCH $\{(\bar{1}\bar{1}\bar{1}),
(2\bar{1}\bar{1}), (2\bar{1}1)\}$ planes (approximately parallel to $ab$-plane)
can result in 1-D growth (stacked along with $c$-axis).
